[gtk+] (13 commits) ...broadway: Add some (disabled) debugging tools

[Alexander Larsson <alexl src gnome org>]

Summary of changes:

  d284c3f... broadway: Re-add seat and core device creation (*)
  907e071... broadway: Add a texture cache (*)
  1820362... broadway: Deserialize node tree in server (*)
  e43f031... broadway: Add div for container nodes (*)
  46c4869... broadway: Prepare for implementing diff (*)
  3d4a932... broadway: Add broadway_node_equal (*)
  521b09c... broadway: Send diffs of node trees (*)
  c300737... broadway: Improve logging (*)
  f5e0986... vulkan: Don't crash if vkEnumeratePhysicalDevices fails (*)
  d95cbb2... gtksnapshot: Merge trivial clip duplicates (*)
  d43008b... broadway: Fix texture hash function (*)
  af890e6... broadway: Don't send node updates to browser if nothing cha (*)
  61ea8e8... broadway: Add some (disabled) debugging tools (*)

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