Get rid of Gtk-WARNING **: Unknown property: GtkHBox.expand
Merge pull request #61 from monsta/patch-1

Get rid of Gtk-WARNING **: Unknown property: GtkHBox.expand
Set XDG_CURRENT_DESKTOP if unset

XDG_CURRENT_DESKTOP is used by glib >= 2.42 at g_desktop_app_info* functions

Original GNOME commit: https://git.gnome.org/browse/gnome-session/commit/?id=1db085ce7e5197b28ab24a3ec54d888efe98fcb4
Closes https://github.com/mate-desktop/mate-session-manager/pull/62
gtk-3.14: invisible session properties dialog

Fix invisible session properties dialog when running with gtk-3.14

Closes https://github.com/mate-desktop/mate-session-manager/pull/63
Sync translations with transifex