Blender Git Loki

Fixes for changing layout with workspace

Changing workspace should now change to the active layout of the workspace just fine.
Screen/workspace changing is still a bit hacky since we can't do it during normal handlers. Not sure how we could do it instead, for now I'm just copying hacks from screen changing.

Fix layout changing when changing workspace

Move active screen layout into the active workspace

Changing the workspace now also changes the layout. Note that there is a drawing issue here so you'll have to move the window to see the change. There is also a crash when closing Blender, need to investigate some more.
This commit also cares for compatibility, we simply create a new workspace for each screen layout of the old file.

I want to avoid any low-level access of workspace related data, instead everything should go through an API. Thus I also added some API functions for workspaces.
To store bScreens (aka layout) using a ListBase in a workspace, I had to add a bScreen wrapper, called WorkSpaceLayout.

Add/use worksace API functions for adding/changing/deleting

Also removed anything that influences workspace user count, from now on it's simply *always* 1.

Add workspace to bContext

Add a workspace browsing button to Info Editor header

And actually make it work.

Store a workspace in each window

Some details need to be figured out still (Windows should probably be able to share an active workspace).

Initially add WorkSpace ID type