[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:

  8a338b9... Add code to load and save pngs
  fdcb23e... Load pngs without gdk-pixbuf
  5e1c5f9... Save pngs without gdk-pixbuf
  b8ea990... Add tests for the png loader
  120b9ff... Add code to load and save tiff files
  a7b9aa9... Load tiffs without gdk-pixbuf
  5d008d8... Add tests for the tiff loader
  4f78c8c... Add gdk_texture_save_to_file
  85c6be7... Use our png loader for content (de)serialization
  b26bc0e... Use our tiff loader for content (de)serialization
  d150682... Add contentserializer tests for textures
  2adcdb1... Add code to load jpegs
  d09f20a... Load jpegs without gdk-pixbuf
  b0f7566... Add tests for the jpeg loader

Commits added to the branch:

  9972202... Add code to load and save pngs
  da828ec... Load pngs without gdk-pixbuf
  5f9ce4a... Save pngs without gdk-pixbuf
  789b7ca... Add tests for the png loader
  fe6a5e8... Add code to load and save tiff files
  0e0801a... Load tiffs without gdk-pixbuf
  88b12e7... Add tests for the tiff loader
  722914c... Add gdk_texture_save_to_file
  e79d8d5... Use our png loader for content (de)serialization
  b3dcdb4... Use our tiff loader for content (de)serialization
  ab0a34b... Add contentserializer tests for textures
  4c36ecb... Add code to load jpegs
  0d08f2d... Load jpegs without gdk-pixbuf
  897f210... Add tests for the jpeg loader