Mostly internal changes, keeping both manipulators
could have worked but there was no point long term.
There are still some glitches to resolve, will work on those next.
This makes manipulator access closer to operators,
and allows Python access.
This adds RNA for manipulators, but not Python registration yet.
- Split draw style into 2x settings:
`draw_style` (enum) & `draw_options` (enum-flag)
- Rename wmManipulator.properties -> properties_edit,
Use wmManipulator.properties for ID-properties.
Note that this area of the API will need further work since
manipulators now have 2 kinds of properties & API's to access them.
Instead use generic 'WM_manipulator_new', adding a new 'setup'
callback (like wmManipulatorGroup.setup) used to initialize type vars.
This moves conventions closer to wmOperator and simplifies exposing to
Python.
While this is work-in-progress from custom-manipulators branch
its stable so adding into 2.8 so we don't get too much out of sync.
- ManipulatorGroupType's are moved out of the manipulator-map and are now
global (like operators, panels etc) and added into spaces as needed.
Without this all operators that might ever use a manipulator in the 3D
view would be polling the viewport.
- Add optional get/set callbacks for non-RNA properties
Needed so re-usable manipulators can control values that
don't correspond to a single properly or need conversion.
- Fix divide by zero bug in arrow manipulator (when moving zero pixels).
