Allow to use -- as seperator in lxc-netstat, otherwise -n from lxc-netstat
collides with netstats -n option (Closes: #641251). 
[Serge Hallyn] update patch to (1) not demand argument for
 exec (breaks) and  (2) set $name not $lxc_name.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>