Blender Git Loki

Don't use undo for manipulator tweak operator

This causes problems when tweaking an operator

Fix divide by zero dragging the arrow

Cleanup: remove redundant access function

Cleanup: use consistent abbreviation for manipulator vars

Manipulator Properties

- Add a different kind of properties that use function callbacks
instead of RNA.
Needed for situations when there isn't 1:1 correspondence
between the manipulator's position and the internal value.
- Move manipulator properties into their own file.

Merge branch 'blender2.8' into custom-manipulators

Cleanup: rename callbacks

Cleanup: remove DNA_manipulator_types.h

Cleanup, rename callbacks

Edit to last commit, add string versions of add-remove

RNA/Py API for runtime add/remove

WindowManager.manipulator_group_type_add/remove

Further changes to manipulator API's.

These changes are intended for operators to register their own
widget-types temporarily, so _every_ operator that uses manipulators
doesn't need to keep them continuously polling the view to check if the
operator is running.

- Register `wmManipulatorGroupType` globally (like all other RNA types).
- Add `wmManipulatorGroupTypeRef` for type-maps to reference groups.
- Remove `wmManipulatorMapType.idname` (spaceid & regionid are enough info).
- Add PERSISTENT flag for `wmManipulatorGroupType`
intended for use with operators so loading a new file for eg doesn't
keep the manipulator type around.

Move manipulator type API into its own file

Support dynamic registration w/ RNA widget types

Dynamically registered types are now correctly initialized in each view.

Remove unused register+init functions

This needs to be split out for dynamic registered types anyway.

Merge branch '28' into custom-manipulators

Merge branch '28' into custom-manipulators

Merge branch '28' into custom-manipulators

Cleanup: consistent naming

Use shorter names for manipulator

Merge branch '28' into custom-manipulators