Added Multihoming feature to LWIP (ability to use more than one network interfaces) for increasing networking reliability.
This involves:
LWIP interface
LWIP IP routing
DNS storage
Sockets (bind to interface name possibility)
possibility to add non default network interface
cellular middleware modifications if cellular connection is used
New classes covered with unit tests: SocketAddress, EthernetInterface, EMACInterface, WiFiAccessPoint.
Also added missing namespace in front of mbed::Callback usages.
EMACInterface is covered by the EthernetInterface unit tests.
Improved the stubs for event queue and nsapi_dns, to allow checking if callback are handled correctly. This involves some memory allocation and deallocation.
The NetworkStackWrapper is not covered as it seems to be deprecated code.