Rename LowLevel.c/.h to USBController.c/.h.
Remove dependancies on the complete <avr/io.h> header in the HighLevel USB driver directory, to ensure less work is required in later (possible) ports.
Add new module source variables to the library core makefile, so that module sources can be added to a project's makefile on a per-module rather than per-file basis.
Fixed all Class drivers to ensure they have appropriate guards on each function to ensure the device is enumerated before running, fixed error codes on all guards to return "DeviceDisconnected" where possble.
Renamed HOST_SENDCONTROL_DeviceDisconnect enum value to HOST_SENDCONTROL_DeviceDisconnected to be in line with the rest of the library enum error codes.
Split out common defines/types from class drivers into a seperate common class driver directory.
Make central USB Class driver dispatch headers, used for both device and host modes.
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.
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the Pipe_IsSetupSent() macro has been renamed to Pipe_IsSETUPSent() and the Pipe_ClearSetupSent() macro is no longer applicable and should be removed - changes made to compliment the new endpoint and pipe bank management API.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.