With this patch, if an unprivileged user has $HOME 700 or
750 and does

lxc-start -n c1

he'll see an error like:

lxc_container: Permission denied - could not access /home/serge.  Please grant it 'x' access, or add an ACL for t he container root.

(This addresses bug pad.lv/1277466)
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>