add 3 lines to netif/bridge netif_pre_up()
if [ -n "$stp" ]; then
brctl stp $interface $stp
fi

add one line to netif/tap net_pre_up()
ifconfig $interface hw ether $mac_addr

this allows the bridge to function as a real switch in your network, and allows the tap interfaces to be given a persistent mac address, which is useful for Virtual Machine networks

http://pastebin.com/FcMU5P76 <- full netif/bridge file
http://pastebin.com/juBPpJfS <- full netif/tap file