Implement delete users and groups

Implement adding a group to a group
Some other small fixups
Add new cmd-line tool ipa-delgroup

ipa-admintools/ipa-deluser

@@ -28,7 +28,7 @@ import xmlrpclib
 import kerberos
 
 def usage():
-    print "ipa-adduser user"
+    print "ipa-deluser user"
     sys.exit(1)
 
 def parse_options():