Merge lp://staging/~unity-team/unity/7.2.2 into lp://staging/unity

Prepare for upstream micro-release 7.2.2. Fixes bugs:
Bug #607796: Launcher, Window management - Dragging and holding a selection over an entry in the Launcher should spread out windows belonging to that application
Bug #727902: Launcher icon highlighting should not switch off as soon the cursor moves after the app spread appears.
Bug #741869: Unity/compiz intercepts Super and Alt keypresses from grabbed windows like VMs.
Bug #754580: Cannot move tabs between multiple Firefox or Chromium windows while using Unity unless windows are both unmaximized, unminimized, and visible.
Bug #839728: Launcher - dragging a item on top of a launcher tile that is a valid drop receptacle in the Launcher should cause that launcher tile to glow
Bug #924840: Keyboard shortcuts overlay text too long
Bug #1281058: [UIFe] The system shutdowns when multiple accounts are open
Bug #1283775: Launcher: icon pips are not always updated properly
Bug #1304882: [Regression] Launcher doesn't reappear fully after hiding from DND
Bug #1305586: Lock screen is unusable when some windows have a keyboard/mouse grab
Bug #1307738: Lockscreen caps lock icon drawn under text entry, should be a white icon.
Bug #1308288: Lockscreen warning icon has no tooltip
Bug #1308323: Shutdown/reboot/login/logout dialogs not scaled after toggling UI scale Edit
Bug #1308911: Clipboard contents are accessible within lockscreen
Bug #1309739: Unity launcher icon edge illumination is offset
Bug #1310200: Indicators disappear at the panel (clementine, dropbox, skype etc)
Bug #1313280: Fullscreen window set to "Always on Top" in single-monitor will hide the lockscreen
Bug #1316005: Panel shadow appears over full screen applications w/ locally integrated menus enabled
Bug #1317348: Switcher (Alt-Tab) does not respect monitor-defined scaling factor
Bug #1317356: Shortcut hint does not respect monitor scaling factor
Bug #1317869: Keyboard shortcuts overlay does not show up when workspaces are enabled at 1366x768
Bug #1320438: Unity launcher auto hide fails on screen unlock using "Super+L"
Bug #1321043: [regression] lock screen bypass with touchpad

Prepare for upstream micro-release 7.2.2.