[gtk] (14 commits) ...Merge branch 'dnd-cleanups' into 'master'

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  228f813... dnd: Drop gdk_drag_drop (*)
  bc2f484... Revert "GdkDrop: drop the priv struct" (*)
  1ea09a3... Add a private struct to GdkDrag (*)
  034f89b... wayland: Drop an unused api (*)
  9cc3e2c... gdkdrag: remove an unused member (*)
  5ce3520... Add a GdkDrag::surface property (*)
  298b6ee... wayland: Stop accessing GdkDrag members (*)
  2d83bb1... x11: Stop using GdkDrag fields (*)
  98ccb67... drop: stop accessing GdkDrag fields (*)
  435f143... x11: Rename a file (*)
  1685232... x11: Set actions on drag (*)
  410d4bc... wayland: Set actions on drag (*)
  3c8b3cb... win32: Stop accessing GdkDrag members (*)
  89f25d1... Merge branch 'dnd-cleanups' into 'master'

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