[gtk] (14 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:

  6664c94... Add code to load and save pngs
  1d664e7... Load pngs without gdk-pixbuf
  b9c93ee... Save pngs without gdk-pixbuf
  f4c462f... Add tests for the png loader
  43f4b9e... Add code to load and save tiff files
  a39b374... Load tiffs without gdk-pixbuf
  823996a... Add tests for the tiff loader
  76839d0... Add gdk_texture_save_to_tiff
  1cbd0d4... Use our png loader for content (de)serialization
  59475d1... Use our tiff loader for content (de)serialization
  9169ff4... Add contentserializer tests for textures
  7a9a3be... Add code to load jpegs
  46cd137... Load jpegs without gdk-pixbuf
  20273e8... Add tests for the jpeg loader

Commits added to the branch:

  544e4f5... Add code to load and save pngs
  ca2bd01... Load pngs without gdk-pixbuf
  1e6df99... Save pngs without gdk-pixbuf
  27a4ef1... Add tests for the png loader
  59f6855... Add code to load and save tiff files
  458eb88... Load tiffs without gdk-pixbuf
  a60d8db... Add tests for the tiff loader
  d2b0ac1... Add gdk_texture_save_to_tiff
  18fd6a3... Use our png loader for content (de)serialization
  3d04632... Use our tiff loader for content (de)serialization
  5effee3... Add contentserializer tests for textures
  f71757d... Add code to load jpegs
  913e825... Load jpegs without gdk-pixbuf
  2254071... Add tests for the jpeg loader