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

Ensure all USB device class drivers have the same three main functions as their interface for consistency.

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.

Commit of new class abstraction APIs for all device demos other than the MIDI demo - not documented yet.

Removed scheduler and memory allocation libraries.

Added new EVENT_USB_StartOfFrame event in the library to indicate the start of each USB frame (when generated).

Removed Tx interrupt from the USBtoSerial demo; now sends characters via polling to ensure more time for the Rx interrupt.

Change USBtoSerial Tx to polling-driven rather than interrupt driven, to ensure more time for the Rx interrupt to be serviced.

Fixed incorrect ENDPOINT_EPNUM_MASK mask preventing endpoints above EP3 from being selected (thanks to Jonathan Oakley).

Removed STREAM_CALLBACK() macro - callbacks now use regular function definitions to clarify user code.

Removed DESCRIPTOR_COMPARATOR() macro - comparators should now use regular function definitions to clarify user code.

USB_HostRequest renamed to USB_ControlRequest, entire control request header is now read into USB_ControlRequest in Device mode rather than having the library pass only partially read header data to the application.

The USB_UnhandledControlPacket event has had its parameters removed, in favour of accessing the new USB_ControlRequest structure.

The Endpoint control stream functions now correctly send a ZLP to the host when less data than requested is sent.

Removed specialized Endpoint_ClearControl* and Pipe_ClearControl* macros in favour of the standard Endpoint_Clear* and Pipe_Clear* macros (Atmel have confirmed no effect from setting FIFOCON on control endpoints).

Changed over all deprecated GCC structure tag initializers to the standardized C99 format (thanks to Mike Alexander).

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

Removed Endpoint_ClearCurrentBank() and Pipe_ClearCurrentBank() in favour of new Endpoint_ClearIN(), Endpoint_ClearOUT(), Endpoint_ClearControlIN(), Endpoint_ClearControlOUT(), Pipe_ClearIN(), Pipe_ClearOUT(), Pipe_ClearControlIN() and Pipe_ClearControlOUT() macros (done to allow for the detection of packets of zero length).

Renamed *_ReadWriteAllowed() macros to *_IsReadWriteAllowed() to remain consistent with the rest of the LUFA API.

Endpoint_IsSetupReceived() macro has been renamed to Endpoint_IsSETUPReceived(), Endpoint_ClearSetupReceived() macro has been renamed to Endpoint_ClearControlSETUP(), the Pipe_IsSetupSent() macro has been renamed to Pipe_IsSETUPSent() and the Pipe_ClearSetupSent() macro is no longer applicable and should be removed - changes made to compliment the new endpoint and pipe bank management API.

Updated all demos, bootloaders and projects to use the new endpoint and pipe management APIs (thanks to Roman Thiel).

Updated library doxygen documentation, added groups, changed documentation macro functions to real functions for clarity.

Removed old endpoint and pipe aliased read/write/discard routines which did not have an explicit endian specifier for clarity.

Removed the ButtLoadTag.h header file, as no one used for its intended purpose anyway.

Corrected AudioInput and AudioOutput demos, to fix endpoint underflows due to rounding in the sample reload timer.

Adjusted sample CTC timer calculations in the AudioOutput and AudioInput demos to account for situations where the division results in a value with no remainder, requiring one to be subtracted from the result (thanks to Robin Theunis).

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.

Corrections to Keyboard demo.

Removed AVRISP_Programmer project due to code quality concerns.

Fixed incorrect/missing control status stage transfers on demos, bootloaders and applications (thanks to Nate Lawson).