Blender Git Loki

Merge branch 'master' into hair_immediate_fixes

Removed block matrix indices storage from ClothSpring struct.

This is not necessary: the implicit solver data can keep track instead
of how many off-diagonal matrix blocks are in use (provided the
allocation limit is calculated correctly). Every time a spring is
created it then simply increments this counter and uses the block index
locally - no need to store this persistently.

Removed unused force arguments for angular bending springs and avoid
redundant calculation for counterforces.

Fix for brackets lost in merge.

Merge branch 'master' into hair_immediate_fixes

Conflicts:
source/blender/blenloader/intern/versioning_270.c

Logic for light position operator.

WIP, operator to tweak the lamp "focus", driven through widgets.

Use the hair shape keys as goal positions (xconst) in the hair solver.

Note that this does not change the natural bending shape of the hair so
far, but only affects the global goal position for now.

Lamp widget:

* Make a lamp widget design for the active lamp.
* Fix some handler errors for widgets + autoupdate for different widget
handles.

Guide hair drawing for hair particles.

Without this the particle system only shows the actual non-simulated
hairs ("guide hairs") during edit mode. These hairs are used for goals
as well, so showing them in the regular viewport is pretty important.

Also the usual hair curves are interpolated along the entire length,
which makes it very difficult to see exact vertex positions, unless
using exact powers of 2 for the segment number and match the display
steps.

Fixed RNA update callbacks to ensure the hair path cache is rebuilt.

Fix for hair shape key ui script.

Fixed some ui script errors.

Fixed some uses of ob->shapenr instead of psys->shapenr.

Replaced the single `ID *from` pointer in shape keys with a more
detailed `owner` struct.

This allows distinction of classic ID block shape keys from particle
system keys.

Evaluate shape keys when building the particle path cache.

Placeholder widget code for spotlamps

Shape key "specials" menu for particle shape keys.

Renamed file to make it consistent with object shapekey operators.

Fix for RNA using ptr->id.data instead of ptr->data for ParticleSystem.