[gnome-shell] (22 commits) ...js/main: Add docs to private function

[Marge Bot <marge-bot src gnome org>]

Summary of changes:

  bcfcacd... st: Use ClutterGrab for StButton implicit grab (*)
  a8a9d4f... st: Use ClutterGrab for StScrollBar implicit grab (*)
  88a8ba0... slider: Use Clutter.grab() for implicit grab (*)
  88d60a7... modalDialog: Make reactive (*)
  81179bb... authPrompt: Make actor reactive (*)
  0e4cd3b... lookingGlass: Use Clutter.grab() for actor picking (*)
  876765d... boxPointer: Do not mute key events while showing (*)
  49b9ae0... appDisplay: Explicitly highlight selected app icon (*)
  f4cae72... main: Use Clutter.grab() underneath Main.push/popModal (*)
  35d293d... overview: Grab on the stage (*)
  05a6b35... overview: Propagate crossing events in cover pane (*)
  bad385d... lookingGlass: Use lookingGlass dialog for modal grab (*)
  5305bee... dnd: Use Clutter.grab() for DnD grab (*)
  f2cca5c... padOsd: Capture events on itself (*)
  3a77d78... loginDialog: Perform grab on the stage actor (*)
  0f315a6... grabHelper: Use Clutter.grab() underneath (*)
  63725ef... popupMenu: Drop unused blockSourceEvents switch (*)
  2709f6c... popupMenu: Refactor focus and key management (*)
  7419674... js: Change main.pushModal to return the Clutter.Grab handle (*)
  21913b4... dialog: Handle key events on self (*)
  21cc534... screenshot: Port to Clutter.Grab (*)
  1dcc6d1... js/main: Add docs to private function (*)

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