When doing reboot test, must add clone_newuser to clone flags, else
we can't clone(CLONE_NEWPID).

If we don't have caps at lxc-start, don't refuse to start.  Drop the
lxc_caps_check() function altogether as it is unused now.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>