It needs to be done from the handler, not the container, since
the container may not have the rights.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

Changelog:
    Jul 22: remove hardcoded path for /bin/chown
    Jul 22: use new lxc-usernsexec

Conflicts:
	src/lxc/lxccontainer.c