Desktop-mode improvements
Fix various issues with regards to the Desktop experience of Lomiri.
Notable changes:
- Fix crash related to a mismatch in saving display configurations
- Hide and disallow the Launcher in Greeter-only mode
- Hiding icons of apps without any surfaces (ie X11 is completely gone on Mir 2.x and pops up on-demand on Mir 1.8)
- Re-enable MirSurfaceItem clipping in windowed mode only
- Resize decorated windows when their surface sizes change with them
- Fix switching workspaces by clicking them in the Spread overview
- Remove dangling windows from the scene under more circumstances
Edited by Alfred Neumayer