Fixes for gnome-session 3.

We run by default with a panel (default gnome-panel) and then run Openbox
without any panel if one cannot be found.

- Adds a fallback session for if a panel (default gnome-panel) not found.
- Removes notifications as a requirement.  Seems to be a legacy thing judging
  from the ubuntu .session files.  Notifications are being provided by
  notify-osd on modern systems, and you can't check for its presence in
  gnome-session (gnome-classic.session always fails because it looks for it, so
  ubuntu falls back to gnome-fallback.session).

Makefile.am

@@ -516,7 +516,8 @@ nodist_xsessions_DATA = \
 	data/xsession/openbox-kde.desktop
 
 dist_gnomesession_DATA = \
-	data/xsession/openbox-gnome.session
+	data/gnome-session/openbox-gnome.session \
+	data/gnome-session/openbox-gnome-fallback.session
 
 dist_noinst_DATA = \
 	data/rc.xsd \

data/gnome-session/Makefile

@@ -0,0 +1,4 @@
+all clean install:
+	$(MAKE) -C .. -$(MAKEFLAGS) $@
+
+.PHONY: all clean install

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

@@ -0,0 +1,6 @@
+[GNOME Session]
+Name=GNOME/Openbox fallback (Safe Mode)
+RequiredComponents=gnome-settings-daemon;
+RequiredProviders=windowmanager;
+DefaultProvider-windowmanager=openbox
+DesktopName=GNOME

data/gnome-session/openbox-gnome.session

@@ -0,0 +1,9 @@
+[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
+DesktopName=GNOME

data/openbox.desktop

@@ -7,6 +7,10 @@ Icon=openbox
 NoDisplay=true
 # name we put on the WM spec check window
 X-GNOME-WMName=Openbox
+# gnome-session autostart
 X-GNOME-Autostart-Phase=WindowManager
 X-GNOME-Provides=windowmanager
+# Ubuntu stuff
+X-Ubuntu-Gettext-Domain=openbox
+# back compat
 X-GNOME-Autostart-Notify=true

data/xsession/openbox-gnome.session

@@ -1,6 +0,0 @@
-[GNOME Session]
-Name=GNOME/Openbox
-RequiredComponents=gnome-panel;gnome-settings-daemon;
-RequiredProviders=windowmanager;notifications;
-DefaultProvider-windowmanager=openbox
-DefaultProvider-notifications=notification-daemon