Adding OTG and embedded host to 16U firmware

yes, I was looking at Tweensy earlier, it would fit the bill but his postal charges to Europe are a killer. USPS "upto 3 weeks, no tracking" $10 or something like $60-80 for UPS.

Since he's fixed all the memory leaks that affects strings and SD, for Tweensy, I'd like to support his boards but for the delivery problem.