Turn off USB functionnality / SerialUSB.end() not implemented

SerialUSB.end() function in cores/arduino/USB/CDC.cpp is not implemented.

When trying to jump from an application to an other (using this function http://pastebin.com/FyjkXJR2), the new application doesn't start if the USB cable is plugged in. I tried to do a SerialUSB.end() rigth before jumpApplication(), but the function is not implemented. I think something should be done to be able to stop all USB activity. Maybe it is not the aim of this function. If so, please point me to the right one :smiley:

Thanks!