[gtk] (8 commits) Non-fast-forward update to branch gamma-shenanigans

[Matthias Clasen <matthiasc src gnome org>]

The branch 'gamma-shenanigans' 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:

  57d5a73... Support loading and saving 16bit pngs
  7949ab3... Support 16-bit floating point textures
  f800cb3... fix up premultiplication
  baeb682... Support 32-bit floating point textures
  f7a413b... Add gdk_texture_save_to_file
  de6d4c5... Support loading and saving float textures
  8a11cf5... Redo the conversion setup for memory formats
  c13d70e... Allow conversion to hdr formats
  2a501a8... Add gdk_texture_download_float

Commits added to the branch:

  e908853... Support loading and saving 16bit pngs
  a262491... Support 16-bit floating point textures
  1fd72df... Support 32-bit floating point textures
  a4a2318... Add gdk_texture_save_to_file
  50c05d0... Support loading and saving float textures
  11dc025... Redo the conversion setup for memory formats
  ceb3b7a... Allow conversion to hdr formats
  7bc268c... Add gdk_texture_download_float