Initial support for Python/Manipulator integration
from 'custom-manipulators' branch.
Supports:
- Registering custom manipulators & manipulator-groups.
- Modifying RNA properties, custom values via get/set callbacks,
or invoking an operator.
- Drawing shape presets for Python defined manipulators (arrow, circle, face-maps)
Limitations:
- Only float properties supported.
- Drawing only supported via shape presets.
(we'll likely want a way to define custom geometry or draw directly).
- When to refresh, recalculate manipulators will likely need
integration with notifier system.
Development will be continued in the 2.8 branch
Python wasn't able to set 'OperatorType.prop', which is used by uiButGetStrInfo().
add 'bl_property' to python operators which is assigned to OperatorType.prop when registering.
(api docs coming next)
