Move /etc/init.d/sysctl to index 00 and add hotplug script that applies
interface specific sysctls for interfaces that only appear later - this
allows to reliably configure per-interface parameters in sysctl.conf, e.g.
to disable ipv6 autoconfig on a specific iface.
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36129 3c298f89-4303-0410-b956-a3cf2f4a3e73