Blender Git Loki

partial fix, take proper constraint locations and rotations into account when converting back to objects, but todo, take own object transform into account too

added names for meshislands, can now convert back to named objects, added load / save support (was missing)

fixes for the monitoring logic of plastic constraints, again

Assets: add uuid to linked data, write and read it from file.

Note that this is only very first steps, I think we'll need to 'propagate'
uuid to all data used/linked by asset itself, otherwise most things won't get
updated/reloaded. Still have to think about this.

fixes for correct rotation calculation in prefractured and external mode

Merge branch 'asset-engine' into asset-experiments

Merge branch 'id-remap' into asset-experiments

Merge branch 'master' into asset-engine

Merge branch 'master' into id-remap

Conflicts:
source/blender/editors/space_outliner/outliner_tools.c

used more exact angle calculation method for external mode, different formulae for tolerances, and some cleanup of obsolete stuff.

added material handling (so meshislands get correct materials from original objects) and added plastic tolerance values, which are taken into account with special simulation mode only.

reduced a performance bottleneck when adding many constraints in a loop, do not trigger modifier updates or set validate flags or even call bullet functions... but todo is to keep a useful update mechanism

Merge branch 'asset-engine' into asset-experiments

Merge branch 'id-remap' into asset-experiments

Merge branch 'master' into asset-engine

Merge branch 'master' into id-remap

Merge branch 'master' into id-remap

Conflicts:
source/blender/blenkernel/intern/library_query.c

Fixing problems with macOSX opengl. Thanks to Marcelo Varanda.

avoid resetting cache (and iterating possibly through the rigidbody group) when adding mesh constraints

attempt to make mesh island packing faster when being called in a loop, create the dm only once after packing