Rigify: removed "from rigfy import X" statements where possible.

This makes it much easier for e.g. someone to branch Rigify for
custom purposes, since there won't be weird name conflicts.

Also changed from using __import__() for dynamic imports to using
importlib.import_module().  This simplifies the code and should
be more robust.

Finally, misc pep8 cleanups.

13 files changed, 92 insertions, 72 deletions

diff --git a/rigify/rigs/basic/copy.py b/rigify/rigs/basic/copy.py
index be04830b..9deb0e11 100644
--- a/rigify/rigs/basic/copy.py
+++ b/rigify/rigs/basic/copy.py
@@ -19,9 +19,10 @@
 # <pep8 compliant>
 
 import bpy
-from rigify.utils import copy_bone
-from rigify.utils import strip_org, make_deformer_name
-from rigify.utils import create_bone_widget
+
+from ...utils import copy_bone
+from ...utils import strip_org, make_deformer_name
+from ...utils import create_bone_widget
 
 
 class Rig:
diff --git a/rigify/rigs/basic/copy_chain.py b/rigify/rigs/basic/copy_chain.py
index 4b4f0c85..a56e65c3 100644
--- a/rigify/rigs/basic/copy_chain.py
+++ b/rigify/rigs/basic/copy_chain.py
@@ -19,11 +19,12 @@
 # <pep8 compliant>
 
 import bpy
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone
-from rigify.utils import connected_children_names
-from rigify.utils import strip_org, make_deformer_name
-from rigify.utils import create_bone_widget
+
+from ...utils import MetarigError
+from ...utils import copy_bone
+from ...utils import connected_children_names
+from ...utils import strip_org, make_deformer_name
+from ...utils import create_bone_widget
 
 
 class Rig:
diff --git a/rigify/rigs/biped/arm/deform.py b/rigify/rigs/biped/arm/deform.py
index 4ed2cc47..ad6d8634 100644
--- a/rigify/rigs/biped/arm/deform.py
+++ b/rigify/rigs/biped/arm/deform.py
@@ -18,13 +18,15 @@
 
 # <pep8 compliant>
 
-import bpy
 from math import acos
+
+import bpy
 from mathutils import Vector, Matrix
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone, put_bone
-from rigify.utils import connected_children_names
-from rigify.utils import strip_org, make_mechanism_name, make_deformer_name
+
+from ....utils import MetarigError
+from ....utils import copy_bone, put_bone
+from ....utils import connected_children_names
+from ....utils import strip_org, make_mechanism_name, make_deformer_name
 
 
 def align_roll(obj, bone1, bone2):
diff --git a/rigify/rigs/biped/arm/fk.py b/rigify/rigs/biped/arm/fk.py
index 77031227..e27e8541 100644
--- a/rigify/rigs/biped/arm/fk.py
+++ b/rigify/rigs/biped/arm/fk.py
@@ -19,14 +19,15 @@
 # <pep8 compliant>
 
 import bpy
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone
-from rigify.utils import connected_children_names
-from rigify.utils import strip_org, make_mechanism_name
-from rigify.utils import get_layers
-from rigify.utils import create_widget, create_limb_widget
 from rna_prop_ui import rna_idprop_ui_prop_get
 
+from ....utils import MetarigError
+from ....utils import copy_bone
+from ....utils import connected_children_names
+from ....utils import strip_org, make_mechanism_name
+from ....utils import get_layers
+from ....utils import create_widget, create_limb_widget
+
 
 class Rig:
     """ An FK arm rig, with hinge switch.
diff --git a/rigify/rigs/biped/arm/ik.py b/rigify/rigs/biped/arm/ik.py
index 31383b54..50ae72a9 100644
--- a/rigify/rigs/biped/arm/ik.py
+++ b/rigify/rigs/biped/arm/ik.py
@@ -18,15 +18,17 @@
 
 # <pep8 compliant>
 
-import bpy
-from mathutils import Vector
 from math import pi, acos
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone
-from rigify.utils import connected_children_names
-from rigify.utils import strip_org, make_mechanism_name, insert_before_lr
-from rigify.utils import create_widget, create_line_widget, create_sphere_widget
+
+import bpy
 from rna_prop_ui import rna_idprop_ui_prop_get
+from mathutils import Vector
+
+from ....utils import MetarigError
+from ....utils import copy_bone
+from ....utils import connected_children_names
+from ....utils import strip_org, make_mechanism_name, insert_before_lr
+from ....utils import create_widget, create_line_widget, create_sphere_widget
 
 
 def angle_on_plane(plane, vec1, vec2):
diff --git a/rigify/rigs/biped/leg/deform.py b/rigify/rigs/biped/leg/deform.py
index 76f751f1..0d0bb2a7 100644
--- a/rigify/rigs/biped/leg/deform.py
+++ b/rigify/rigs/biped/leg/deform.py
@@ -18,13 +18,15 @@
 
 # <pep8 compliant>
 
-import bpy
 from math import acos
+
+import bpy
 from mathutils import Vector, Matrix
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone, put_bone
-from rigify.utils import connected_children_names, has_connected_children
-from rigify.utils import strip_org, make_mechanism_name, make_deformer_name
+
+from ....utils import MetarigError
+from ....utils import copy_bone, put_bone
+from ....utils import connected_children_names, has_connected_children
+from ....utils import strip_org, make_mechanism_name, make_deformer_name
 
 
 def align_roll(obj, bone1, bone2):
diff --git a/rigify/rigs/biped/leg/fk.py b/rigify/rigs/biped/leg/fk.py
index 3d776cb7..497c110d 100644
--- a/rigify/rigs/biped/leg/fk.py
+++ b/rigify/rigs/biped/leg/fk.py
@@ -19,14 +19,15 @@
 # <pep8 compliant>
 
 import bpy
-from mathutils import Vector
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone
-from rigify.utils import connected_children_names, has_connected_children
-from rigify.utils import strip_org, make_mechanism_name
-from rigify.utils import get_layers
-from rigify.utils import create_widget, create_limb_widget
 from rna_prop_ui import rna_idprop_ui_prop_get
+from mathutils import Vector
+
+from ....utils import MetarigError
+from ....utils import copy_bone
+from ....utils import connected_children_names, has_connected_children
+from ....utils import strip_org, make_mechanism_name
+from ....utils import get_layers
+from ....utils import create_widget, create_limb_widget
 
 
 class Rig:
diff --git a/rigify/rigs/biped/leg/ik.py b/rigify/rigs/biped/leg/ik.py
index 7d01a602..98f4a3eb 100644
--- a/rigify/rigs/biped/leg/ik.py
+++ b/rigify/rigs/biped/leg/ik.py
@@ -18,15 +18,17 @@
 
 # <pep8 compliant>
 
-import bpy
-from mathutils import Vector
 from math import pi, acos
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone, flip_bone, put_bone
-from rigify.utils import connected_children_names, has_connected_children
-from rigify.utils import strip_org, make_mechanism_name, insert_before_lr
-from rigify.utils import create_widget, create_line_widget, create_sphere_widget, create_circle_widget
+
+import bpy
 from rna_prop_ui import rna_idprop_ui_prop_get
+from mathutils import Vector
+
+from ....utils import MetarigError
+from ....utils import copy_bone, flip_bone, put_bone
+from ....utils import connected_children_names, has_connected_children
+from ....utils import strip_org, make_mechanism_name, insert_before_lr
+from ....utils import create_widget, create_line_widget, create_sphere_widget, create_circle_widget
 
 
 def align_x_axis(obj, bone, vec):
diff --git a/rigify/rigs/finger.py b/rigify/rigs/finger.py
index 15e1bbac..ff2fc560 100644
--- a/rigify/rigs/finger.py
+++ b/rigify/rigs/finger.py
@@ -18,15 +18,17 @@
 
 # <pep8 compliant>
 
+import re
+
 import bpy
-from mathutils import Vector
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone
-from rigify.utils import connected_children_names
-from rigify.utils import strip_org, make_mechanism_name, make_deformer_name
-from rigify.utils import create_widget, create_limb_widget
 from rna_prop_ui import rna_idprop_ui_prop_get
-import re
+from mathutils import Vector
+
+from ..utils import MetarigError
+from ..utils import copy_bone
+from ..utils import connected_children_names
+from ..utils import strip_org, make_mechanism_name, make_deformer_name
+from ..utils import create_widget, create_limb_widget
 
 
 class Rig:
diff --git a/rigify/rigs/misc/delta.py b/rigify/rigs/misc/delta.py
index d13f7d4e..873515d8 100644
--- a/rigify/rigs/misc/delta.py
+++ b/rigify/rigs/misc/delta.py
@@ -18,11 +18,13 @@
 
 # <pep8 compliant>
 
-import bpy
 from math import acos
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone
-from rigify.utils import org_name, make_mechanism_name
+
+import bpy
+
+from ...utils import MetarigError
+from ...utils import copy_bone
+from ...utils import org_name, make_mechanism_name
 
 
 class Rig:
diff --git a/rigify/rigs/neck_short.py b/rigify/rigs/neck_short.py
index a94b3cef..f7814a0c 100644
--- a/rigify/rigs/neck_short.py
+++ b/rigify/rigs/neck_short.py
@@ -19,13 +19,15 @@
 # <pep8 compliant>
 
 import bpy
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone, new_bone, put_bone
-from rigify.utils import connected_children_names
-from rigify.utils import strip_org, make_mechanism_name, make_deformer_name
-from rigify.utils import obj_to_bone, create_circle_widget
 from rna_prop_ui import rna_idprop_ui_prop_get
 
+from ..utils import MetarigError
+from ..utils import copy_bone, new_bone, put_bone
+from ..utils import connected_children_names
+from ..utils import strip_org, make_mechanism_name, make_deformer_name
+from ..utils import obj_to_bone, create_circle_widget
+
+
 script1 = """
 head_neck = ["%s", "%s"]
 """
diff --git a/rigify/rigs/palm.py b/rigify/rigs/palm.py
index f055dffb..acef0529 100644
--- a/rigify/rigs/palm.py
+++ b/rigify/rigs/palm.py
@@ -18,13 +18,15 @@
 
 # <pep8 compliant>
 
-import bpy
-from math import cos, pi
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone
-from rigify.utils import strip_org, deformer
-from rigify.utils import create_widget
 import re
+from math import cos, pi
+
+import bpy
+
+from ..utils import MetarigError
+from ..utils import copy_bone
+from ..utils import strip_org, deformer
+from ..utils import create_widget
 
 
 def bone_siblings(obj, bone):
diff --git a/rigify/rigs/spine.py b/rigify/rigs/spine.py
index 56888c8a..332c6f43 100644
--- a/rigify/rigs/spine.py
+++ b/rigify/rigs/spine.py
@@ -26,13 +26,13 @@ from math import floor
 
 import bpy
 from mathutils import Vector
-from rigify.utils import MetarigError
-from rigify.utils import copy_bone, new_bone, flip_bone, put_bone
-from rigify.utils import connected_children_names
-from rigify.utils import strip_org, make_mechanism_name, make_deformer_name
-from rigify.utils import obj_to_bone, create_circle_widget, create_compass_widget
 from rna_prop_ui import rna_idprop_ui_prop_get
 
+from ..utils import MetarigError
+from ..utils import copy_bone, new_bone, flip_bone, put_bone
+from ..utils import connected_children_names
+from ..utils import strip_org, make_mechanism_name, make_deformer_name
+from ..utils import obj_to_bone, create_circle_widget, create_compass_widget
 
 script = """
 main = "%s"