lxc-alpine: allow /dev/full

The template creates /dev/full for the container but needs also give
permission to access it.

Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
lxc-busybox: don't copy temp mounts into mtab

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>