Redocumented all device demos, now that they have changed over to the new USB class drivers.

Added C linkage to class drivers for C++ support.

Added prefixes to most of the class driver constants to prevent name clashes.

Create a new function pointer type in StreamCallbacks.h for endpoint/pipe stream callbacks, to make stream function prototypes clearer.

Removed all user pipe/endpoint interrupt APIs, added internal library support for interrupt driven control endpoints when in device mode by defining INTERRUPT_CONTROL_ENDPOINT token and passing it to the compiler via the -D switch.

Endpoint configuration is now refined to give better output when all configurations have static inputs - removed the now useless STATIC_ENDPOINT_CONFIGURATION compile time token.

Fixed USB_RemoteWakeupEnabled flag never being set (the REMOTE WAKEUP Set Feature request was not being handled).

Renamed the FEATURELESS_CONTROL_ONLY_DEVICE compile-time token to CONTROL_ONLY_DEVICE.

Removed "Host_" section of the function names in ConfigDescriptor.h, as most of the routines can now be used in device mode on the device descriptor.

Renamed functions in the HID parser to have a "USB_" prefix and the acronym "HID" in the name.

Further module-level documentation updates.

Renamed NO_CLEARSET_FEATURE_REQUEST compile time token to NO_FEATURELESS_CONTROL_ONLY_DEVICE and expanded its function to also remove parts of the Get Status chapter 9 request, to further reduce code usage.