Support /var/lib/lxc/$C/priority to start up containers in order of priority.

[tyru]

Just a little hack.
but I think it's useful to define start up order.

[tyru]

Such as DHCP, LDAP server must start and be running before other hosts.
if this patch was applied, you can define start up order like this. (default priority is 10)

# echo 1 >/var/lib/lxc/dhcp/priority
# echo 2 >/var/lib/lxc/dns/priority
# echo 3 >/var/lib/lxc/www/priority

(just example, I never tried that situation)

[phbaer]

Good idea, nice feature!