Blender Git Loki

Keymap: check modal keymap item poll function

Fixes T56591: Vertex/Edge slide C-Key fails

Tool System: make armature extrude use drag event

Extrude tool was calling click-extrude.

Merge branch 'blender2.8' into greasepencil-object

Fix some errors in Simplify and Subdivide

Merge branch 'master' into blender2.8

Build environment: Ensure Python is using static ffi

Surely, need to compile ffi first :)

Good news are: Python seems static enough now!

Build environment: Make sure Python is linkign against static Zlib

There is system-wide libz development package installed by default,
needed for some other dependencies. This patch ensures Python will
use our own self-compiled Zlib.

Fix some UI script errors after recent keyword changes.

Differential Revision: https://developer.blender.org/D3654

Fix several things

Merge branch 'blender2.8' into greasepencil-object

Fix T56529: Viewport ColorChage with Overlay "Fade 3D Objects"

Fix space text script - keyboard for labels

I guess multi-line ui elements were not covered in the cleanup scripts.

RNA: make mesh add methods use required arg 'count'

Cleanup: fix merge small mistake

Merge branch 'blender2.8' into greasepencil-object

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

Cleanup: pep8

Fixed file data blocks linking error.

Fix T56530, T56523: collection visiblity toggling wrong after recent changes.

Cleanup: compiler warnings.

Cleanup: remove debug code.