[mutter] (16 commits) Non-fast-forward update to branch wip/garnacho/wayland-startup-notification

[Carlos Garnacho <carlosg src gnome org>]

The branch 'wip/garnacho/wayland-startup-notification' was changed in a way that was not a fast-forward 
update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  058c48d... core: Refactor startup notification into a separate object
  1b449f5... wayland: Update gtk-shell protocol file to v3
  b28bff8... wayland: Implement gtk-shell v3

Commits added to the branch:

  55eef2d... cursor-renderer-native: Re-use cogl's gbm device (*)
  50099c4... wayland: use glib function for fetching timestamp (*)
  5b0eabe... wayland: Implement support for wp_relative_pointer (*)
  bc8ec2d... wayland: Add global to surface coordinate helper (*)
  f0f638d... Move out generic math parts out of the native barrier imple (*)
  5256440... native: Update to new constrain callback API (*)
  020ae58... wayland: Add "painting" signal to surface actor (*)
  e2efc85... wayland: Make the pending surface state a GObject (*)
  495c894... Implement support for the wp_pointer_constraints protocol (*)
  bc1dd1c... MetaBorder: Use float constants and functions instead of do (*)
  bc47b19... wayland: Use the event coordinates when sending pointer mot (*)
  a70a2c3... MetaPointerConfinementWayland: Support non-rectangular conf (*)
  9611661... native: Don't wait for a new input event to wrap the pointe (*)
  aaa0244... core: Refactor startup notification into a separate object
  63c91f9... wayland: Update gtk-shell protocol file to v3
  9f35b58... wayland: Implement gtk-shell v3

(*) This commit already existed in another branch; no separate mail sent