USB device stack; Added getter method for terminal_connected;

Fork of USBDevice by mbed official

Example of use:

#include "mbed.h"
#include "USBSerial.h"

USBSerial  pc;
DigitalOut blue_led(P0_20);

int main() {
    blue_led = 1;
    while(!pc.getTerminal_connected()); //Wait for serial terminal to connect...
    while(1) {
        blue_led = 0;
        wait(0.2);
        blue_led = 1;
        wait(0.2);
    }
}
Revision:
64:fe3884917848
Parent:
44:d2638fcd76d9
--- a/USBSerial/USBCDC.cpp	Tue May 03 00:16:32 2016 +0100
+++ b/USBSerial/USBCDC.cpp	Sat Oct 01 04:43:09 2016 +0000
@@ -284,3 +284,7 @@
     };
     return configDescriptor;
 }
+
+bool USBCDC::getTerminal_connected(){
+    return terminal_connected;
+}