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
Merge pull request #86 from mtwebster/unredirect

Improvements to unredirect windows