Blender Git Loki

Use better algorithm for arrow widget back transform.

We now use plane/line intersection which seems to work quite well and
agrees to great extent with the transform system as well. There still
some small discrepancy but may also be related to scaling.

WIP cage transform.

This also includes code for the node editor but probably
will try a different use case first.

Nicer hashing functionality for sim debugging using a variadic macro
to support multiple hash identifiers.

Using explicit hashing functions for every sim debug call defeats the
purpose of having a quick feedback system. Now this can be done simply
by passing an arbitrary number of hash inputs (integers) at the end of
the function calls, which are then combined by a system of variadic
macros (based on the ELEM feature). Up to 8 identifiers are supported
currently, but more could be added easily if needed.

Merge branch 'master' into gooseberry

Merge branch 'hair_immediate_fixes' into gooseberry

Conflicts:
release/scripts/startup/bl_ui/properties_particle.py
source/blender/editors/physics/particle_edit.c
source/blender/makesdna/DNA_modifier_types.h
source/blender/physics/intern/BPH_mass_spring.cpp
source/blender/physics/intern/hair_volume.cpp
source/blender/physics/intern/implicit.h
source/blender/physics/intern/implicit_blender.c
source/blender/physics/intern/implicit_eigen.cpp

Merge branch 'master' into hair_immediate_fixes

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

Merge branch 'master' into gooseberry

Some tweaking of value ranges for hair target density and removed
density factor (already included in grid velocity).

Ensure View3D fx when using them, prevents some crashes with old files

Fix SSAO not being constant in camera view.

Inverted effect of target density was unstable, the divergence term
needs to be substracted instead.

Use dedicated debug values in cloth settings instead of abusing unused
other values.

Fixed wrong stride values used for offsetting the index of Eigen values.

The Eigen solver for hair grids uses an extra margin of 1, which means
greater stride values.

Merge branch 'terrible_consequencer' into gooseberry

Conflicts:
source/blender/editors/space_sequencer/sequencer_draw.c

Gooseberry request, snap frame marker during frame setting by holding
ctrl key

Merge branch 'master' into terrible_consequencer

Conflicts:
source/blender/editors/space_sequencer/sequencer_draw.c

Hair grid code was using an invalid hair segment at each hair end with
zero vectors, leading to bad density values.

Merge branch 'viewport_experiments' into gooseberry

A bunch of debug drawing changes.

Fix T42596 crash with DOF on MacOS.

Compiler failed on last shader and failure was not detected. However
compiler error also revealed a blurring error as well :)