Update the gnome-session support for version 3.9.90 in Ubuntu Trusty

This change is not backward compatible unfortunately. The format of
the gnome-session .session files has changed, such that every part
of the session is now listed on the RequiredComponents line.

data/gnome-session/openbox-gnome-fallback.session

@@ -1,6 +1,4 @@
 [GNOME Session]
 Name=GNOME/Openbox fallback (Safe Mode)
-RequiredComponents=gnome-settings-daemon;
-RequiredProviders=windowmanager;
-DefaultProvider-windowmanager=openbox
+RequiredComponents=openbox;gnome-settings-daemon
 DesktopName=GNOME

data/gnome-session/openbox-gnome.session

@@ -1,9 +1,4 @@
 [GNOME Session]
 Name=GNOME/Openbox
-RequiredComponents=gnome-settings-daemon;
-# Try load with the gnome-panel and use the fallback if we can't load a panel
-RequiredProviders=windowmanager;panel
-DefaultProvider-windowmanager=openbox
-DefaultProvider-panel=gnome-panel
-FallbackSession=openbox-gnome-fallback
+RequiredComponents=openbox;gnome-settings-daemon;gnome-panel;nautilus-classic;gnome-flashback-services
 DesktopName=GNOME