Usb documentation needed

[odinthenerd]

Design goals for the USB abstraction were

• complete static binding
• fully configurable (to the point of micromanaging memory strategy)
• unit tested for everything upwards from the HAL

Although I think these can be/have been met the interfaces between the HAL and the USB::Device as well as the interface between the USB::Device and the device classes could not be implemented as cleanly as I had hoped.
We need to do a good job of documenting the contracts between the Usb::Device and the Hal as well as the contracts between the Usb::Device and the interface class(es).

[odinthenerd]

@CvRXX hey I can offload this onto you now that its your research topic ;)