make sure to check c->lxc_conf is not NULL before dereferencing it.

Signed-off-by: S.Çağlar Onur <caglar@10ur.org>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
allow setting/getting lxc.loglevel and lxc.logfile via set_config_item/get_config_item API calls

Signed-off-by: S.Çağlar Onur <caglar@10ur.org>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>