[gtk] (20 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:

  7d7e000... Refactor gdk_gl_context_upload_texture slightly
  b935ffc... Support 16bit textures
  af08757... Add private api to download textures
  2ff5ae4... Support loading and saving 16bit pngs
  1708a1d... Support 16-bit floating point textures
  e96e493... Support 32-bit floating point textures
  1203922... Add gdk_texture_save_to_file
  f86bc6a... Support loading and saving float textures
  2193c15... Redo the conversion setup for memory formats
  e12de89... Allow conversion to hdr formats
  ef2d528... Add gdk_texture_download_float
  980cc99... Add async png load/save code
  ef2dba4... Use our png loader for content (de)serialization
  dab5669... Add async tiff load/save code
  5d175a4... Use our tiff loader for content (de)serialization
  39fe08c... Add a jpeg loader
  043f4aa... Load jpegs without gdk-pixbuf
  2d93be2... Add vecorized half-float conversion
  5a11376... Improve half-float memory conversions

Commits added to the branch:

  c86733b... Update Turkish translation (*)
  c2279b0... Refactor gdk_gl_context_upload_texture slightly
  e049e63... Support 16bit textures
  39ee2fc... Add private api to download textures
  68f07b7... Support loading and saving 16bit pngs
  360e1f1... Support 16-bit floating point textures
  e38e376... Support 32-bit floating point textures
  a1626fb... Add gdk_texture_save_to_file
  4b02164... Support loading and saving float textures
  f6a257b... Redo the conversion setup for memory formats
  c0144c1... Allow conversion to hdr formats
  229302e... Add gdk_texture_download_float
  4af3b6b... Add async png load/save code
  51a06f0... Use our png loader for content (de)serialization
  b3daa42... Add async tiff load/save code
  32cb2f3... Use our tiff loader for content (de)serialization
  290591f... Add a jpeg loader
  32fb555... Load jpegs without gdk-pixbuf
  17719d2... Add vecorized half-float conversion
  dafe186... Improve half-float memory conversions

(*) This commit already existed in another branch; no separate mail sent