[gtk] (11 commits) Non-fast-forward update to branch wip/otte/guadec2018

[Benjamin Otte <otte src gnome org>]

The branch 'wip/otte/guadec2018' 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:

  0ce5bde... gtk: Add GtkZoom
  15b2f35... mediafile: Export gtk_media_file_get_impl_type()
  a56a0e2... demos: Add GTK4 lightning talks talk

Commits added to the branch:

  93c5455... iconhelper: Plug memleak (*)
  3439862... gtkmediafile: Don't leak all the images (*)
  9fb3b84... rendernode: Make offset nodes use floats (*)
  53e3428... gtk: Add GtkZoom
  0ed2c3a... mediafile: Export gtk_media_file_get_impl_type()
  49138f2... demos: Add GTK4 lightning talks talk
  34f99a6... paintable: Fix return_if_fail() statements
  a2c61e6... xxx: talk
  f765d86... widgetpaintable: Redo implementation
  4bd3b0b... xxx: talk
  2de1586... widgetpaintable: Add a hack to make recursion not infloop

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