Make Low Level host demos use void pointers for the configuration descriptor, to prevent warnings when passed to the altered configuration descriptor parsing routines.

Added preprocessor checks to give a human readable error when the class drivers are used when the incompatible NO_STREAM_CALLBACKS compile time option is used.

Add new manual pages detailing the advantages of LUFA over the official Atmel USB AVR stack, and reasons why LUFA should be used over a built-from-scratch USB stack.