[package] firewall:
- defer firewall start until the first interface is brought up by hotplug, fixes race conditions on slow devices
- create a file lock during firewall start and wait for it in hotplug events, prevents race conditions between start and addif
- start firewall actions in background from hotplug handler since the firewall itself fires further hotplug events which results in a deadlock if not forked off
- get loaded state direcly from the uci binary since updated value is not recognized by config_get after uci_set_state
- bump package revision to r2
SVN-Revision: 21486