[gtk] (15 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:

  544e4f5... Add code to load and save pngs
  ca2bd01... Load pngs without gdk-pixbuf
  ae91d71... Save pngs without gdk-pixbuf
  6ccc978... Add tests for the png loader
  fcce2d9... Add code to load and save tiff files
  2499ef2... Load tiffs without gdk-pixbuf
  d199d97... Add tests for the tiff loader
  49b9095... Add gdk_texture_save_to_tiff
  2aa01b2... Use our png loader for content (de)serialization
  54d173e... Use our tiff loader for content (de)serialization
  1e7f473... Add contentserializer tests for textures
  6eff7fb... Add code to load jpegs
  1b25063... Load jpegs without gdk-pixbuf
  b1cb8ea... Add tests for the jpeg loader

Commits added to the branch:

  2c6e890... Add code to load and save pngs
  43ceb17... Load pngs without gdk-pixbuf
  f43abcc... Save pngs without gdk-pixbuf
  6588a1d... Add tests for the png loader
  2cb047b... Add code to load and save tiff files
  7912033... Load tiffs without gdk-pixbuf
  6661eaa... Add tests for the tiff loader
  e519ca7... Add gdk_texture_save_to_tiff
  e357e0b... Use our png loader for content (de)serialization
  c2a89b1... Use our tiff loader for content (de)serialization
  67f4dd4... Add contentserializer tests for textures
  9160317... Add code to load jpegs
  ad1c206... Load jpegs without gdk-pixbuf
  d6720d9... Add tests for the jpeg loader
  63b7f86... fixup contentserializder test