[gtk] (9 commits) Non-fast-forward update to branch image-loading

[Matthias Clasen <matthiasc src gnome org>]

The branch 'image-loading' 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:

  122ef6d... Add code to load and save pngs
  eb5395f... Load pngs without gdk-pixbuf
  bd3b70b... Add code to load and save tiff files
  d68c68a... Load tiffs without gdk-pixbuf
  d8b2068... Add gdk_texture_save_to_file
  6d8b7a7... Use our png loader for content (de)serialization
  b78d88c... Use our tiff loader for content (de)serialization
  f3b7ffa... Add code to load jpegs
  3c6fe13... Load jpegs without gdk-pixbuf

Commits added to the branch:

  b199607... Add code to load and save pngs
  be7e9a7... Load pngs without gdk-pixbuf
  a5e9751... Add code to load and save tiff files
  0e0e1c1... Load tiffs without gdk-pixbuf
  2bcb032... Add gdk_texture_save_to_file
  8ec4cb0... Use our png loader for content (de)serialization
  47e763a... Use our tiff loader for content (de)serialization
  3f7a5aa... Add code to load jpegs
  6b341f8... Load jpegs without gdk-pixbuf