changed default value of settings
---------------------------------

Most of the interesting configuration changes made by this
package are in debian/kali-defaults.gsettings-override.

gdm sessions
------------

Special diversions are made with gdm's xsessions files so that the
default.desktop file defining the default session that gdm launches
is the session that Kali wants.

/usr/share/gdm/BuiltInSessions/default.desktop is moved away
while /usr/share/xsessions/gnome-fallback.desktop is renamed
into default.desktop.

NOTE: If gnome-flashback is not installed, the default will be
the first session by alphabetical order.