Drop input, rendering et al on loss of focus
Fix xserver build-dep version
Different input dropping
Fix potential damage-tracking race

We need to clear the damage region for the buffer that will be submitted
to Mir. After calling mir_surface_swap_buffers it's possible that the current
buffer will already have been advanced, so we'd clear damage on the wrong buffer.
Merge remote-tracking branch 'github/vladmir-upstreaming' into vladmir-upstreaming
Add DPMS support
Use default Mir socket if mirSocket is unset
Squash with output improvements
Miscellaneous fixes
Squash with DPMS
Woot!