Remove all Host mode class demos other than the CDCHost class driver demo, so that they can be re-added as they are made once the host mode class framework is designed.
Fixed USB_Host_SendControlRequest() not re-suspending the USB bus when initial device ready-wait fails.
Fixed USB Pad regulator not being disabled on some AVR models when the USB_OPT_REG_DISABLED option is used.
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.
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.