doap: Call this "GNOME Session Manager"

It's common for projects to include "GNOME" in the name - this is less
ambiguous.

gnome-session.doap

@@ -4,7 +4,7 @@
          xmlns:gnome="http://api.gnome.org/doap-extensions#"
          xmlns="http://usefulinc.com/ns/doap#">
 
-  <name xml:lang="en">Session Manager</name>
+  <name xml:lang="en">GNOME Session Manager</name>
   <shortdesc xml:lang="en">The GNOME Session Manager</shortdesc>
   <description>The GNOME Session Manager is in charge of starting the core
 components of the GNOME desktop, and applications that should be launched at