Added brace guards to macros with parameters to prevent unintended changed evaluation of the macro expression.
Minor code cleanups (remove redundant comments, fix spacing, etc.).
Remove VBUS events - not needed as the library takes care of VBUS detection and feedback on supported AVRs via the USB_Device_Connected and USB_Device_Disconnected events.
Fixed incorrect Host state assignment in the incomplete BluetoothHost demo.
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.