-- fix#754
-- make_unique function is not available for gcc<=4.8.x
by enabling this flag in through install script or through
cmake such systems can build latte correctly
--we dont need to remove our old desktop files any more.
Our users that use Latte through master branch installation
should have already updated their desktop file properly.
--update the desktop file naming in order to comply with
new guidelines. Concerning also wayland. The new desktop
file is named to org.kde.latte-dock.desktop
Michail Vourlakos
Johan Smith Agudelo Rodriguez