Moved USBtoSerial demo the Projects directory, as it is simply an expanded CDC demo. Added const qualifier to Endpoint/Pipe stream write routines.

Move check for devices not supporting internal serials in demos which make use of USE_INTERNAL_SERIAL to Descriptors.c from Descriptors.h so that the warning is only generated at most once per compilation.

Set all CDC and MassStorage device mode demos (LowLevel and ClassDriver) to use the USE_INTERNAL_SERIAL feature, add compile time warnings for devices which do not have an internal serial.

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.

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

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.

Deleted StdDescriptors.c, renamed USB_GetDescriptor() to CALLBACK_USB_GetDescriptor, moved ConfigDescriptor.c/.h from the LUFA/Drivers/USB/Class/ directory to LUFA/Drivers/USB/HighLevel/ in preperation for the new USB class APIs.

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.