This patch simply adds a preliminary check for the built-in Add Curve Extra Objects add-on.
The check basically prevents a traceback in the console.
Without this patch the add-on still functions as intended, just with a console prompt.
Reviewed By: Blendify
Differential Revision: https://developer.blender.org/D9666
Bumped version to 0.1.2
Pep8 cleanup
Consistent property definitions
Remove star imports
Some small UI fixes
Reorder the submenu items types Alphabetically
Add Curve braid: merge in the bpybraid and braid scripts
since they are relatively small
Add Simple Curve - use a property group for scene props
Add list of Menus and Panels available in the User Preferences