Bumped version to 0.5.1
Pep8 cleanup
Imports as tuples
Removed the operator LoadRandomEditOperator from the file
random_editor.py since is not working / implemented
The related function random_edit_from_random_subset
from functions.py was removed too, since it is not used
removed some of the unused variables
UI cleanup - better alignment of buttons
Preferences added a list of assigned shortcuts
Make a separate drop down for dependentand / experimental tools
Fix a few bugs - sound strip attribut UI call
Add some try except blocks
