Only release if the current _connect_status is CONNECTING. If the semaphore is released many times for each connect, then the next connect will not wait(), as it will be able to decrement the semaphore imediatelly.
Make Nanostack an OnboardNetworkInterface, implementing
add_ethernet_interface so it can use EMAC drivers.
Can now be used via EthernetInterface, and be the system's default
network stack.
Legacy support for NanostackEthernetInterface retained. Some
restructuring of mesh interface code to fit into the
OnboardNetworkStack:::Interface system.