[gtk/gtk-3-24] (15 commits) ...Merge branch 'wip/carlosg/controllers-backport' into 'gtk-3-24'

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  747be0f... gtk: Add GtkEventControllerScroll (*)
  7b8c036... eventcontrollerscroll: Emit ::scroll for -1/+1 discrete ste (*)
  448551f... gtkeventcontrollerscroll: Add some docs (*)
  84d3bfb... gtk: Remove CONSTRUCT_ONLY flag from GtkEventControllerScro (*)
  e7af341... Avoid excess notification for GdkEventControllerScroll::fla (*)
  8b2c3a8... Add a simple motion eventcontroller (*)
  1f9de70... Add x/y to GtkEventControllerMotion::enter (*)
  e0f3e8a... gtk: Add GtkEventControllerKey (*)
  a32933b... eventcontrollerkey: Add function to forward stuff elsewhere (*)
  ecf9fa6... gtkeventcontrollerkey: Add get_group() call (*)
  7793aab... gtkeventcontrollerkey: Add ::focus-in/out signals (*)
  a846395... gtk: Add GtkGestureStylus (*)
  effdf3a... demos: Add "Paint" demo (*)
  9ee6077... sm scroll (*)
  cc73241... Merge branch 'wip/carlosg/controllers-backport' into 'gtk-3

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