Blender Git Loki

Allow changing to workspace that's open in another window

This needs more work still.

Store active screen-layout per window

Fix crashes on file read

Move window level workspace data into struct managed by workspace code

Merge branch 'blender2.8' into workspaces

Get basic button handling in top bar to work

Support topbar drawing for all draw methods

Add/use iterator for all areas in screen (not just screen-layout)

Draw info editor buttons in topbar

Basically copies most of the UI definitions from info editor to top bar.

Create global areas for all non-temp windows

Get rid of hardcoded screen-size calculation

Screen size is the rectangle that can be used by screen layouts, so it
excludes global areas.

Merge branch 'workspaces' into topbar

Conflicts:
source/blender/blenloader/intern/readfile.h
source/blender/blenloader/intern/versioning_280.c

Merge branch 'blender2.8' into workspaces

Merge branch 'blender2.8' into workspaces

Merge branch 'blender2.8' into workspaces

Merge branch 'blender2.8' into workspaces

Merge branch 'blender2.8' into workspaces

Support render layer per workspace

We decided to keep workspace and scene render layer separate for now,
but in future they'll probably be either unified or there are going to
be ways to sync them.

Merge branch 'blender2.8' into workspaces

Conflicts:
source/blender/makesrna/intern/rna_space.c

Merge remote-tracking branch 'origin/blender2.8' into workspaces