Fix for walk navigation not working with stereo camera (multiview)

Reviewers: campbellbarton

Differential Revision: https://developer.blender.org/D917
API Docs: remove hardcoded self from shellscript
Fix own commit: broke add background image
Transform: correct flag -> bool
Transform: fix for fcurve transform crash

counting handles was out of sync, now use exact same logic.
Fix T42653, solidify modifier not displaying correctly under edit mode.

Basically, our drawing code assumed we always use the edit mesh
materials, which can be different from the derived mesh
materials in modifiers doing overrides. We usually we want to use the
derived mesh when it is available instead.

There are two fixes here for both solid and textured mode. Unfortunately
the fixes do not help to make the display code less labyrinthian but I
expect this "should work" (tm and famous last words)

Solid mode fix is 95% from Bastien, thanks!
Addition/correction to previous commit:

subsurf needs the same modifications in its derived mesh function or
materials don't get updated at all anymore.
Partial Fix T42652: Transform falloff for mesh islands

This doesn't currently do anything clever when a single vertex is shared by multiple islands
(uses closest only).
Cleanup: duplicate headers
Fix graph editor rename button resetting focus when escaping from it.
This is a copy of what the outliner does and seems to work.
Cycles: Code cleanup, remove dead code
Cycles: Only report exporting curves if there are particle systems on the object
Install_deps: switch to OSL 1.5.11 (ammended with blender-fixes).
Fix for previous commit (forgot to update rev UID, sorry).
Material not set in edit derived meshes after last material modification
commits.
Cleanup GPU: get rid of some extremely legacy draw code.

Basically this commit gets rid of most of the derived mesh immediate mode
drawing (cases such as subsurf excluded). Even when VBO is turned off
in user preferences, we still use vertex arrays, which are very similar to
VBOs but memory is client side. Vertex arrays are OpenGL 1.1 so compatibility
is not an issue here.

Reviewers: campbellbarton, sergey, jwilkins

Differential Revision: https://developer.blender.org/D919
Delete GPU buffers if preference changes.
Cleanup: unused headers
Cleanup: unused headers
Cleanup: unused headers