Commit of new class abstraction APIs for all device demos other than the MIDI...
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.