Fix T41843: World preview not updating when changing world.

NC_SCENE | ND_WORLD was not handled by buttons space...
Fix part of T41739: Solid 3DView not updating when enabling/disabling nodal material.

There are other similar update issues with mat nodes and solid 3DView, but need agreement
on proposed patch from other devs in this area first!
Math Lib: use higher precision for vector printing

Only use for debugging, where precision is often important.
Fix T41849: Knife fails with small lens

knife cursor depth could be projected behind the view with a wide angle lens.
Fix T41850: Knife fails with mesh behind view

Was using first vertex for depth (which could be anywhere),
now use the view-pivot.

was also copying uninitialized vector into knife_find_closest_* return values (confused debugging).
Fix T41840: bpy.context.object.collision.thickness_inner has no effect on cloth.

Only change the tip to stress that, in fact, cloth sim does not use inner thickness at all,
only outer one, through the Collision modifier, afaik.
Fix T41851: Useless ID selector UI element for sequencer's Sound strips

Currently, this pointer prop is not editable, and making it so does not seem
to be trivial (sound strip seems to use the filepath path, not the soundID pointer?),
so just hide the matching UI item.
Cleanup: pep8
Text Editor: reload missed adding new-line

Logic for load/reload was duplicated, Fix T28087 missed reload.

De-duplicate, also replace stat -> BLI_stat
Fix T41761, muting not working with texture nodes

This was disabled to fix T41349, however seems that if we don't pass
delegates for muted nodes everything work fine.
OSX/cmake: OSX 10.10 must be used with cmake 3.0.0 minimum, older thinks 10.6 is higher than 10.10 :)
Cleanup: style, spelling
Fix T41861: Loopcut wire incorrect mode-switch

also didn't preview or select correctly.
Fix for edge-order flipping on subdividing wire

Extruding a subdivided edge would create flipped faces.
Fix T41862: Autosmooth & multi-material glitch
Fix for missing Freestyle sections in the Blender Python API documentation.

Freestyle sections of the API docs were empty due to Freestyle module reorganization
in commit rB6498b96ce7081db039354228213d72e8c70bd3aa.

Module __all__ property was added to submodules so as to properly exclude irrelevant
documentation elements such as mathutils.Vector.
Fix for a run-time error in sphinx_doc_gen.py on Windows.
Cleanup: use static sets where possible
Palettes:

Avoid having an invalid active index if user deletes a color.

Also attempt to set active color on clicking (Not working yet but fix
coming soon)