Blender Git Loki

Cleanup: Remove unused stuff

Cleanup: Move GP-Object specific UI panels to the appropriate file

3D Annotations: Restore ability to access annotations from the 3D view

For now, the "gpencil" context properties work as follows:
* If the active object is a GP Object, the GP data associated with
that is returned
* Otherwise, the Scene's GP data (i.e. annotations) are used

We may need to revise this later. But in the meantime, I'm restoring
this so that we have a quick way of figuring out what parts of the
annotation tool workflow are currently broken.

TODO: Note some struct members that should be moved to runtime data struct

Annotations: Properly initialise annotation datablocks

Annotations: Repurpose an ancient/rarely-used flag to indicate that a GP datablock is used for annotations

Cleanup: Move comments to sit above the right structs

Annotations: First steps towards having working annotations again

Copy-back (from 2.8) and split out "Annotations" drawing operator/rendering
code from the "GP Object" versions of the same code.

Notes:
* All "annotation" related things are now in the annotate_*.c files,
while "drawgpencil.c" and "gpencil_paint.c" are for the GP Object only
now. This will simplify maintenance of the two different usecases,
as the GP Object versions are significantly more complicated and filled
with extra cruft.

* The general "Grease Pencil" keymap (i.e. the one that allows DKEY+LMB-drag
to draw) is now for annotation usage only. For GP Objects, you can add a
blank GP Object, enter Draw Mode, and start drawing.

Code Changes:
* Removed all 2D drawing-code entrypoints from drawgpencil.c

* Cleaned up most of the annotate_paint.c and annotate_draw.c code
to remove stuff that annotations won't use (e.g. brushes, palettes,
fancy line effects, etc.) As much as possible, these have been restored
back to a pre 2.77 state - with the notable exception of per-layer
Onion Skinning, for which the settings were removed already.

Cleanup: Remove all mention of annotations from GP drawing operator

Set again mix pass to DEPTH_LESS

Using ALWAYS for this pass is wrong because when using several objects, only the less z-depth object is drawn.

Revert "Fix wrong engine name"

This reverts commit 7c3c2561705afb2c7eae905df727f9861248737b.

Temp fix to compile

There is a problem with the generator for themes, and this is a temp fix while Campbell fix the generator,

Merge branch 'blender2.8' into greasepencil-object

Increase multisample texture precission

When use FX get glitches.

Fix wrong engine name

Merge branch 'blender2.8' into greasepencil-object

Fix struct typo name errors

Fix FXAA problem when drawing

The internal passes never must check z-depth values, only in the final pass.

Compile fixes after merge

Merge branch 'blender2.8' into greasepencil-object

# Conflicts:
# source/blender/editors/gpencil/gpencil_interpolate.c
# source/blender/editors/gpencil/gpencil_paint.c