Log Message:
Update digikam to 4.4.0

4.4.0:
* Slideshow support multi-monitors computer and use a new OSD widget.
  Users can also change Tags and Labels through keyboard shortcuts.
* New keyboard shortcut to switch on/off color managed view for thumbnails
  and preview.
* New keyboard shortcuts to improve usability while photo review (as to
  switch focus on text edit widget, or to toggle tags view). It's also
  possible to navigate between pictures using PageUp/PageDown while
  editing properties through captions/tags sidebar.

4.3.0:
* New option to display all non geo-located images from collections.
* New notification event when kio-slave cannot be started. OSX event
  notifier is now used to dispatch notifications under Mac.
* New action to exclude items without rating with items filter (see details
  on this blog entry).

4.2.0:
* New view on left sidebar to search quickly items with assigned Labels.
* On tags tree-view a new option to show items with no tag.

4.1.0:
* The face management feature has seen huge improvements and includes fixes
  for some problems introduced in recent releases.
* The detection and recognition of faces is now more robust and suitable
  for production.
* All icon views now have a new overlay to identify photos that have
  geo-location information, making it easier for users to search albums for
  photos with GPS coordinates.
* The maximum thumbnail size is now 512 pixels, up from 256 pixels
  previously, improving their appearance on high-resolution displays.

4.0.0:
* A new tool dedicated to organize whole tag hierarchies.
* A new maintenance tool dedicated to parse image quality and auto-tags
  items automatically using Pick Labels.
* Showfoto thumbbar is now ported to Qt model/view in order to switch later
  full digiKam code to Qt5.
* A lots of work have been done into Import tool to fix several
  dysfunctions reported since a very long time.
* This release is now fully ported to Qt4 model-view and drop last
  Q3-Support classes.
* This release include also the multi-core CPU support for severals tools
  which require a lots of computing, as Sharpen, LocalContrast, Noise
  Reduction, and all visual effects tools.