This should take care of most of the class property conversions to
use the new annotation format (colon instead of equals) for
assignment in 2.80. There may still be a few edge cases that
were missed.
Bumped version to 3.1.3
Pep8 Cleanup
Consistent prop definitions
Fix crash with reload related to Property group still being used
was related to the order of register - use register_class instead
Restore global undo setting in case of failure in the
calc_callback function with a try except block
Fixed wrong order of multiplication (mat*vec) in Game Prop Visulizer.
Added overlay limit prop to VGroupsWeights addon to prevent Blender hangups, uses a mix of bm.select_history and bm.verts (since select_history doesn't support lasso, box and similar selection types).
