[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:

  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

Commits added to the branch:

  7bafbef... Add gdk_texture_new_from_bytes
  d4ca53b... Add code to load and save pngs
  a627ffb... Load pngs without gdk-pixbuf
  12a8d1c... Save pngs without cairo
  a3b1381... Add tests for the png loader
  2a06072... Add gdk_texture_save_to_png_bytes
  a29680c... Add code to load and save tiff files
  a20405b... Load tiffs without gdk-pixbuf
  d6748a5... Add tests for the tiff loader
  61796cf... Add gdk_texture_save_to_tiff
  3a57792... Use our own loaders for content (de)serialization
  9241367... Add contentserializer tests for textures
  0764672... Add code to load jpegs
  e9e2f48... Load jpegs without gdk-pixbuf
  c898f8e... Add tests for the jpeg loader