USB MSD HID composite device hello world

Dependencies:   USBDevice mbed

Revision:
0:61e5ecd27a36
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBDevice.lib	Mon Jan 21 12:03:05 2013 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/USBDevice/#f8f057664123