AP_Motors_Time_test.pde: use hal.scheduler->micros instead of gettimeofday
UARTDriver: config. file descriptor as non-blocking
UARTDriver: UART-like TCP sockets, check for ":wait"
UARTDriver: Remove the additional portNumber offset

The socket is being launched in (_base_port + portNumber) port
following SITL impl. In order to avoid confusions portNumber has
been set to 0.