VIX-175 Serial Port handling

The exception was occuring in the buttonOk_click event when it was
looking for the port name.  This should not have been hit because
validation should have failed since there were no serial ports.  I found
that the validate method in the serialportconfig.cs file would return
true in the event that the validation failed.  I changed the default to
return false if you have no ports and if you do have ports it will go
through the validation looking for port, baudrate and databits.  If you
have these values it returns true else it returns false.

The buttonOk_click event will now work correctly, since you have no port
information your only option is to cancel out of the dialog box.