[gtk] (20 commits) Non-fast-forward update to branch gst.gl.win32

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

The branch 'gst.gl.win32' 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:

  0ed89b3... media/gstreamer: Support using GL for video for Windows
  3b7ea76... gtkgstsink.c: Support EGL on Windows as well
  0f14e3e... gtkgstsink.c: Fix up thinko
  d0a002b... gtkgstsink.c: Avoid g_setenv()
  6f5c5dc... gtkgstsink.c: Win32: Limit GL API to gles2 when using EGL
  2173117... gstglsink.c: Some cleanups
  c2db8aa... gtkgstsink.c: Check GST_GL_HAVE_PLATFORM_EGL correctly
  365c546... gtkgstsink.c: Call gst_gl_display_filter_gl_api() always on

Commits added to the branch:

  fb6c6c8... checkbutton: Don't allow to uncheck radios by activating th (*)
  bff7ac4... popover: Update docs (*)
  430be6f... Merge branch 'popover-docs' into 'master' (*)
  0017b4b... icons: Fix switch-off icon (*)
  94b0907... Merge branch 'wip/exalm/switch-icons-2' into 'master' (*)
  ab6a5be... Fix documentation syntax (*)
  8ba16eb... Documentation fixes (*)
  7fe0610... introspection: Stop using allow-none (*)
  4a0d3d7... docs: Reduce redundancy (*)
  345edb8... Merge branch 'doc-tweaks' into 'master' (*)
  f5bd9f7... Merge branch 'wip/exalm/check-activate' into 'master' (*)
  a78c592... media/gstreamer: Support using GL for video for Windows
  93c5369... gtkgstsink.c: Support EGL on Windows as well
  d04df76... gtkgstsink.c: Fix up thinko
  ecedf94... gtkgstsink.c: Avoid g_setenv()
  1c5aa08... gtkgstsink.c: Win32: Limit GL API to gles2 when using EGL
  884a2b0... gstglsink.c: Some cleanups
  7925c38... gtkgstsink.c: Check GST_GL_HAVE_PLATFORM_EGL correctly
  ed7be6f... gtkgstsink.c: Call gst_gl_display_filter_gl_api() always on
  4d8d6f2... gtkgstsink.c: Acquire GstGL API manually if needed

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