Some upstream fixes
Support _NET_WM_BYPASS_COMPOSITOR and _NET_WM_DONT_BYPASS_COMPOSITOR
Improve unredirect heuristic

See:
https://git.gnome.org/browse/mutter/commit/?id=90f2a3ae4ca205f7cbbc2daeba2ab7cfa5ed1613
Fix uninitialized variable
upchain finalize()-methods to the respective parents as described here:
https://developer.gnome.org/gobject/stable/gobject-memory.html
Merge branch 'unredirect' of https://github.com/mtwebster/muffin
Merge branch 'upchain-finalize' of https://github.com/Cobinja/muffin