Remove use of avr-libc specific ATOMIC_BLOCK, replace with a new per-architecture set of inline functions to retrieve and manipulate the global interrupt enable bit for each architecture.
Add in documentation for the USB controller common interrupt routine which must be linked to the interrupt controller in the user application on the AVR32 UC3 architecture.
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.