[gtk] (16 commits) Non-fast-forward update to branch tracing

[Matthias Clasen <matthiasc src gnome org>]

The branch 'tracing' 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:

  883e186... gdk: Add a profiler
  e1d2394... Add a way to start the profiler
  ac74359... frame clock: Add tracing
  e92a1f0... gsk: Add some more profiler apis
  e73c482... gsk: Add tracing to the gl renderer
  76bd6f1... gsk: Add tracing to the vulkan renderer
  4e0c461... GtkApplication: Add a profiler dbus api
  2cc0efa... Add docs

Commits added to the branch:

  4ff578d... Fix the compiler warning, again (*)
  730b52b... testsuite: Add blur node testcase (*)
  b3c4320... node editor: Do some simple syntax highlighting (*)
  e847c03... gl renderer: Fix blur nodes with radius 0 (*)
  feddf5a... Detect CUPS ≥ 1.7 (*)
  ed31ea3... cups: Use non-deprecated API (*)
  3377133... Require CUPS >= 2.0 (*)
  5a57866... Merge branch 'cups-deprecation-warnings' into 'master' (*)
  032bb45... gdk: Add a profiler
  9e40642... Add a way to start the profiler
  1660bac... frame clock: Add tracing
  c541fa9... gsk: Add some more profiler apis
  b09a095... gsk: Add tracing to the gl renderer
  64454a7... gsk: Add tracing to the vulkan renderer
  18127be... GtkApplication: Add a profiler dbus api
  ef446de... Add docs

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