Fixed windows serial connectivity bug

I fixed the windows serial connectivity problem. The problem was that, in the Windows platform case, the "self.port" variable was not properly set (in the code it said just "port" instead of "self.port") and therefore, the default value '/dev/tty.MindWaveMobile-DevA' of the "self.port" variable was never overwritten.

In addition to that, I added a print statement which shows which port is being used. This shows the user which COM port is used by default (COM5, in case of Windows).