[j-nsp] commit script to prevent duplicate service def' on SRX?

[Phil Mayers]

To save me the work, does anyone know of a commit script that will 
prevent people defining services which duplicate the JunOS or existing 
user-defined ones?

Are the built-in defs (under 
"groups/junos-defaults/applications/application/$name") in the candidate 
XML config? In which case it's easy, but if not, what the best way to 
get them?