Blender Git Loki

WIP commit, basically introducing a few things here:

* highlighted vs active widget.

Active widget takes all input and basically highjacks drawing of all
other widgets in the widgetmap.

* operator names for widgets. Now widgets will spawn operators based on
names that are passed on them. They will also modify a named property of
the operator and pass it on, after which operator can process it.

Manipulator:

* Fix error in plane manipulator handling.
* Don't show manipulator widgets on paint modes.

Only detect active widget on mousemoves. Now handler operates on
mouseclick (bound to change)

Merge branch 'master' into wiggly-widgets

Ring widgets:

Add a clipping style, just like manipulator

Add space for facegroup storage

Widgets:

* Move lamp operators to a proper place
* Store a list of widgets to avoid polling too many times
* Fix wrong indices when widgetgroup was not used.
* Lamp widget now uses an arrow widget. This will be refined to make a
nice prototype for operator/widget interaction.

Use a property to make the transform operator widget driven.

Design is still pending here, but for now just use to not remove widget
display.

Change dial to something that resembles current rotation widget better.

Dial widget, used in rotation manipulator code.

The widget can still change in the future, also widget styles can always
be used to create new widget visualizations.

Implement non-3D drawing per widget.

Basically, 3D widgets stay the same size whatever the zoom is in 3D
view. Ported over from manipulator code.

Merge branch 'master' into wiggly-widgets

Widgets:

* Add option for shaded/non shaded widgets
* Normalize arrow widget size to 1.0 so size is predictable. Probably
will use the same scheme for other widgets as well

All translation axis now drawn and operated through the widget system.

* Manipulator Y 3D arrow moved and rotated correctly.
* Light manipulator doing undo now
* Scons should be fixed.

Green widget handles y translation properly.

ManipulatorGroup customdata.

Make WidgetGroup data private.

WidgetGroup now handles updating the manipulator properties.

Still not hooked new arrow widget to the system

Add python exporter that exports a mesh in a C file in a renderer-ready
format (vertices + normals + triangle vertex indices)

This will allow us to create widgets in blender instead of defining them
programmatically.

May also support facegroups for different colors in the future though
they must be somehow tied to the UI colors.

Enable depth testing for widgets.

Especially if we have many widgets on screen, sorting them will be
difficult and for mesh-armature widgets it will be unavoidable if we
want to avoid tweaking "back" surfaces.