man: Mention that standard GTK args are also accepted.

man/virt-manager.pod

@@ -74,6 +74,8 @@ on the host.
 
 =back
 
+Standard GTK options like --g-fatal-warnings are also accepted.
+
 =head1 AUTHOR
 
 Written by Daniel P. Berrange and Cole Robinson.

src/virt-manager.py.in

@@ -115,8 +115,9 @@ def drop_stdio():
 def parse_commandline():
     optParser = optparse.OptionParser(version=appversion,
                                       usage="virt-manager [options]")
-
     optParser.set_defaults(uuid=None)
+    optParser.epilog = ("Also accepts standard GTK arguments like "
+                        "--g-fatal-warnings")
 
     # Generate runtime performance profile stats with hotshot
     optParser.add_option("--profile", dest="profile",