[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:

  c472844... Add code to load and save pngs
  03c76ac... Load pngs without gdk-pixbuf
  c4f9e66... Save pngs without gdk-pixbuf
  7164f38... Add tests for the png loader
  0e4020d... Add code to load and save tiff files
  189bb02... Load tiffs without gdk-pixbuf
  cede3cd... Add tests for the tiff loader
  e1ee30c... Add gdk_texture_save_to_tiff
  f55faba... Use our png loader for content (de)serialization
  2b82d12... Use our tiff loader for content (de)serialization
  20583e6... Add contentserializer tests for textures
  6645c8d... Add code to load jpegs
  a9ca889... Load jpegs without gdk-pixbuf
  09547c9... Add tests for the jpeg loader

Commits added to the branch:

  2e34646... Add code to load and save pngs
  26445f0... Load pngs without gdk-pixbuf
  59f2cce... Save pngs without gdk-pixbuf
  aef9f03... Add tests for the png loader
  a698097... Add code to load and save tiff files
  96f9209... Load tiffs without gdk-pixbuf
  96c1312... Add tests for the tiff loader
  051fb9e... Add gdk_texture_save_to_tiff
  8e5f52b... Use our png loader for content (de)serialization
  4b700ea... Use our tiff loader for content (de)serialization
  3e33b45... Add contentserializer tests for textures
  f1aaa00... Add code to load jpegs
  4af5bc0... Load jpegs without gdk-pixbuf
  846b946... Add tests for the jpeg loader