Nucleo F4x1RE: Typos in previously untested code. message() does not exist, return value from void function, missing inclusion of errno.h.  From Sébastien Lorquet

apps/examples/bridge:  Lots of fixes.  I think it is working although I have still have host firewall issues in testing

Due to limitations in port unique-ness, have to use unique port numbers in apps/examples/bridge for now

Change CONFIG_NET_RECEIVE_WONDOW to CONFIG_NET_ETH_TCP_RECVWNDO or CONFIG_NET_SLIP_TCP_RECVWNDO in all defconfig files

Netwoek:  Ada a parameter to netdev_register() to indicate the link protocol supported by the driver.  Use this value to replace some logic commited yesterday

ARP:  Add support for the case where there are multiple networks:  One being Etherenet and the other not (say slip or perhaps someday PPP).  In that case, we need to suppress ARP-related operations on the SLIP/PPP interface only