[gtk] (15 commits) Non-fast-forward update to branch matthiasc/for-master

[Matthias Clasen <matthiasc src gnome org>]

The branch 'matthiasc/for-master' 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:

  ac50a24... macos: Fix a compiler warning
  ea40108... treeviewcolumn: Clip header buttons

Commits added to the branch:

  b09087d... droptarget: Rename :drop to :current-drop (*)
  96fc5dc... mediastream: Some more api renaming (*)
  56c486a... Merge branch 'drop-target-name-collision' into 'master' (*)
  85b595b... gdksurface-win32.c: Fix formatting for popup functions (*)
  ba7ec29... gdksurface-win32.c: Fix up popup placement (*)
  1056451... Merge branch 'media-stream-name-collision' into 'master' (*)
  1abbf00... Merge branch 'fix-3793' into 'master' (*)
  e6c4dbf... spinner: Behave like any other icon (*)
  e59e9ad... Merge branch 'wip/otte/for-master' into 'master' (*)
  fad4c60... Update Portuguese translation (*)
  1bda665... Merge branch 'matthiasc/for-master' into 'master' (*)
  352898a... inspector: fix compilation with broadway (*)
  8df2cce... Merge branch 'wip/chergert/fix-broadway-build' into 'master (*)
  22827f2... macos: Fix a compiler warning
  d92f8a1... treeviewcolumn: Clip header buttons

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