[vala] (8 commits) Non-fast-forward update to branch wip/unicode

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'wip/unicode' 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:

  effb747... glib-2.0: Add UCS-4 and UTF-16 related bindings

Commits added to the branch:

  03f8e29... Fix type checking when using generics in combination with s (*)
  909184e... Add CCode finish_vfunc_name to used attrs (*)
  51438dd... rest-0.7: Fix some ownership problems (*)
  e0aa505... clutter-gst-3.0: Fix Playback.audio_streams/subtitle_tracks (*)
  65b9f18... clutter-gst-2.0: Skip VideoTexture.get_audio_streams/get_su (*)
  6e89b7b... tests: Add async generator example to cover an edge case (*)
  5f851eb... vapi: Update GIR-based bindings (*)
  5c5245d... glib-2.0: Add UCS-4 and UTF-16 related bindings

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