Cleanups to RNDIS device demos. Fix issue in RNDIS demos where the memory would become corrupted due to an incorrect bounds check when iterating over the port state table, causing random resets.

Revert change to Template_Endpoint_Control_R.c, which broke control stream reads.

Remove uneeded ADC.h include in the class driver AudioOutput demo.

Added parameter directions to function parameter documentation.

Added new experimental FAST_STREAM_FUNCTIONS compile time option to speed up stream transfers at the expense of a higher FLASH consumption (needs testing to verify improved throughput).

Move new Class Driver powered demos to a new ClassDriver subdirectory, re-add old low level demos to a LowLevel subdirectory.

Moved out each demos' functionality library files (e.g. Ring Buffer library) to /Lib directories for a better directory structure.

Fixed minor issue with the RNDISEthernet demo DHCP protocol decoder routine using incorrectly named variables (thanks to Jonathan Oakley).

Fixed GenericHIDHost demo report write routine incorrect for control type requests (thanks to Andrei).

All comments in the library, bootloaders, demos and projects have now been spell-checked and spelling mistakes/typos corrected.

Seperated out OTG, Device and Host mode demos into seperate folders for clarity. Adjusted makefiles so that the path to the LUFA library can be set in one place.