Move IP header flags from tcp.h to ip.h and rename IP_FLAGS vs TCPFLAGS.  The problem fixed here is that there IP flags were not available when TCP was disabled.  The IP flags are used in ICMP and IGFMP

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

EFM32 USART setup: Computation of BAUD includes shift; Eliminate additional shift.  From  Pierre-noel Bouteville

Network: netdev_register() must assign the device name appropriately according to the link layer type

Network:  All logic will now handle varialbe length link layer protocol headers within incoming packets.  This permits use of multiple network interfaces with differing data links.  For example, ETHERNET + SLIP