Bevel Fix for nonplanar faces / reflex angles

When beveling two adjacent edges, code used face normal instead
of the face-corner normal (these can be different for nonplanar
faces); the bevel may look uneven in such cases.
Switched to using corner normal, and needed to fix the case
where the edges meet at a reflex angle. Fixed a similar case
when beveling two edges with one non-beveled in between.
Also removed unnecessary argument from offset_meet.
Transform: Warp tool (rewritten)

* Can optionally warp a segment (sets min/max default so it acts as old warp did).
* Can rotate the warp axis (old warp tool was limited to horizontal).
Updating icons for NLA Track "solo" button (as used in standard widgets)
Skeleton of type defines for NlaTrack animchannel
Ported over logic for which animchannel settings are supported by NLA Tracks
Ported code for setting colour of NLA Track anim channel
Added button callback so that toggling solo mode on NLA Tracks now works correctly
Remove old drawing code for NLA Tracks
Anim Editors: Improve some tooltips to be more accurate for the type of editor/data they're shown for

This commit fixes some problems where some tooltips were not adapting
as intended when used for different channel types in different places.
Anim Editors: Ensure that "solo" flag doesn't get accidentally handled on channels which don't support it
NLA Channel Drawing Refactor: Remove rest of old drawing code for NLA Track channels

NLA Track drawing has now been ported over to use the UI widgets
like the rest of the anim channels do in the DopeSheet and Graph
Editors. The main benefit of this for users is that these buttons
will now show tooltips when you hover over them. Hopefully this
will help make the "solo" buttons more discoverable.

I've decided to postpone porting the "Action Line" channels to the
widget system for now, since there are quite a few more issues there
which need quite a bit more time to work through.
Fix T37550: Crash while snaping to curve made from Susane (bug in recent addition)
fix T37411: Transform mouse constraint could fail in some situations.

Was caused by int rounding when an axis was < 1.0.
Code Cleanup: remove unused members for editfont (3D text)
Fix T37543: Multiline 3D Text saved in edit mode breaks on load
Blender Internal:
* Remove Stars feature. This was a quite minimalistic feature and there are
better alternatives with more control (particles for example).

Removal discussed during BCon13 developer meeting and already years before, time to do it..

Reviewed By: brecht
Differential Revision: http://developer.blender.org/D17
* Remove more code for stars, missed those. Sorry!
Fix compile error on MinGW64, time.h is required for gmtime.
Code Cleanup: use strict flags for screw modifier, reduce sign conversion
Blender Internal: Add shader nodes "Separate HSV" and "Combine HSV", same as Cycles' ones.