[gtk] (30 commits) Non-fast-forward update to branch dnd-gestures

[Matthias Clasen <matthiasc src gnome org>]

The branch 'dnd-gestures' 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:

  f8374ee... contentserializer: Fix an annotation
  756ca79... wayland: Fix dnd type negotiation
  50b78cf... Add a GtkDragSource object
  378a9eb... label: Port to GtkDragSource
  d0f5197... linkbutton: Port to GtkDragSource

Commits added to the branch:

  662bcb3... Updated Spanish translation (*)
  21708e4... contentserializer: Fix an annotation (*)
  1841ec4... contentprovider: cosmetic fix (*)
  4b81849... wayland: Fix dnd type negotiation (*)
  e02fd80... dnd: Be safer (*)
  246840b... Add a GtkDragSource object
  76830e4... dnd: Patch up gtk_drag_get_source_widget
  223d499... label: Port to GtkDragSource
  033b519... linkbutton: Port to GtkDragSource
  e54bddc... calendar: Port to GtkDragSource
  454de2d... entry: Port icon dnd to GtkDragSource
  48b3c69... text: Convert to GtkDragSource
  80e0f2e... textbuffer: Add a content provider api
  2e9bc59... textview: Port to GtkDragSource
  7a3d3a0... Add (de)serializers for GdkRGBA
  3e32103... Add a generic callback content provider
  73ec72a... colorbutton: Port to GtkDragSource
  f23340f... colorswatch: Convert to GtkDragSource
  4eb020f... pathbar: Convert to GtkDragSource
  d95abf0... gtk-demo: Convert the clipboard demo to GtkDragSource
  b5fa619... iconbrowser: Port to GtkDragSource
  05c8d41... Add another callback-based provider
  72a818a... iconview: Port to GtkDragSource
  a076454... placessidebar: Port to GtkDragSource
  bb7cf3b... treeview: Port to GtkDragSource
  7dd8cb6... filechooser: Port to GtkDragSource
  51ccbf0... notebook: Port to GtkDragSource
  f27abd1... tests: Convert to GtkDragSource
  e783d80... Remove traditional drag source API
  f22214e... docs: Mention DND in the migration guide

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