Submenus don't open on mouse hover

Status changed to 'Confirmed' because the bug affects multiple users.

This bug was fixed in the package unity8 - 8.15+17.04.20170216.1-0ubuntu1

---------------
unity8 (8.15+17.04.20170216.1-0ubuntu1) zesty; urgency=medium

  [ Albert Astals Cid ]
  * Make menus items close the menu when clicking on them (LP: #1657082,
    #1657399)
  * Clicking on an open menu closes it + test
  * Make the menus and submenus do not go outside the screen when
    popping out
  * Auto open submenus on hover (LP: #1657085)
  * Make the double click on a menu not be maximize the window below
    (LP: #1657079)
  * Make the MenuBar InverseMouseArea eat hover events when there's a
    popup open (LP: #1657763)
  * Make double click on the window decoration maximize (LP: #1657758)
  * Eat hover events when the launcher quicklist is open (LP: #1640776)
  * Remove TODO now that we require Qt > 5.5
  * Serialize two make targets that want to cp to the same target file
    (LP: #1660576)
  * Remove variable that is always false (LP: #1585910)

  [ Daniel d'Andrada ]
  * Consolidate launcher API checks

  [ Lukáš Tinkl ]
  * Fixes for activating minimized windows and restoring fullscreen ones
    (LP: #1656808, #1658937, #1658938)

  [ Michael Zanetti ]
  * move right edge push area up some levels so it can be used on top of
    the indicators
  * fix minimizing/restoring transitions (LP: #1658936)
  * fix some glitches with spread positioning
  * fix jumpy animation when closing an item from the spread
  * Show the wallpaper while the focused app is moving in staged mode
    (LP: #1648251)
  * Update the tutorial to mention the app drawer instead of the dash on
    long left edge swipe (LP: #1658932)
  * prevent hiding the launcher when the mouse hover event is eaten by
    the EdgePushArea (LP: #1657045)
  * properly invalidate the whole model (LP: #1658190)
  * stabilize OrientedShell test (LP: #1658994)

  [ Nick Dedekind ]
  * Added overflow support to application menus.
  * Updated menu colors

 -- Michał Sawicz <email address hidden> Thu, 16 Feb 2017 13:49:18 +0000