[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:

  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

Commits added to the branch:

  13d72ee... Add code to load and save pngs
  bc0d315... Load pngs without gdk-pixbuf
  4f18a34... Save pngs without cairo
  4c64111... Add tests for the png loader
  2568611... Add gdk_texture_save_to_png_bytes
  0c9faea... Add code to load and save tiff files
  b8ee987... Load tiffs without gdk-pixbuf
  9000118... Add tests for the tiff loader
  ee7f2f9... Add gdk_texture_save_to_tiff
  b66fa84... Use our own loaders for content (de)serialization
  f89be80... Add contentserializer tests for textures
  6a83d38... Add code to load jpegs
  0f7c33f... Load jpegs without gdk-pixbuf
  92873e6... Add tests for the jpeg loader
  e794a1a... rendernodeparser: Use gdk_texture_save_to_png_bytes