[gtk] (13 commits) Non-fast-forward update to branch wip.win32.fixes

[Chun-wei Fan <fanchunwei src gnome org>]

The branch 'wip.win32.fixes' 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:

  16c7627... media/gstreamer: Support using GL for video for Windows
  5206c98... gtkgstsink.c: Support EGL on Windows as well
  01e3822... gtkgstsink.c: Fix up thinko
  9444af6... gtkgstsink.c: Avoid g_setenv()
  3e2b41f... gtkgstsink.c: Win32: Limit GL API to gles2 when using EGL
  30ac0cd... gstglsink.c: Some cleanups
  0bf984b... demos/gtk-demo|widget-factory: Temporarily disable gui_app 
  ee17180... gtkgstsink.c: Check GST_GL_HAVE_PLATFORM_EGL correctly

Commits added to the branch:

  c5eb2f5... gdk: annotate Content Serialize/Deserialize return_error (*)
  e9ca8d6... Merge branch 'bilelmoussaoui/gdk-return-error-annotation' i (*)
  0e1d6fb... Update Ukrainian translation (*)
  894adea... Update Ukrainian translation (*)
  b21ff92... media/gstreamer: Support using GL for video for Windows
  1cc6883... gtkgstsink.c: Support EGL on Windows as well
  1f83a23... gtkgstsink.c: Fix up thinko
  280a4c2... gtkgstsink.c: Avoid g_setenv()
  52d0828... gtkgstsink.c: Win32: Limit GL API to gles2 when using EGL
  2113a41... gstglsink.c: Some cleanups
  6c7ba80... demos/gtk-demo|widget-factory: Temporarily disable gui_app 
  9725fbb... gtkgstsink.c: Check GST_GL_HAVE_PLATFORM_EGL correctly
  15b1f9c... gtkgstsink.c: Call gst_gl_display_filter_gl_api() always on

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