fix #371 allow button while using API. also don't let tbeams sleep if they have USB power

src/SerialConsole.cpp

@@ -40,6 +40,8 @@ void SerialConsole::onConnectionChanged(bool connected)
     if (connected) { // To prevent user confusion, turn off bluetooth while using the serial port api
         powerFSM.trigger(EVENT_SERIAL_CONNECTED);
     } else {
+        // FIXME, we get no notice of serial going away, we should instead automatically generate this event if we haven't
+        // received a packet in a while
         powerFSM.trigger(EVENT_SERIAL_DISCONNECTED);
     }
 }