The order and way include macros were structured was chaotic, with no real common thread between files. Try to tidy up the mess with some common scheme, to make things look less messy.
This commit adds support for xdg_shell (the stable version). This was done by first copying the old xdg-shell unstable v6 implementation into a separate .c .h file pair (including various symbol renaming) then porting the old xdg-shell unstable v6 implementation to the new stable version. https://gitlab.gnome.org/GNOME/mutter/merge_requests/5 https://bugzilla.gnome.org/show_bug.cgi?id=791938