Fixed Mouse and Keyboard device demos not acting in accordance with the HID specification for idle periods (thanks to Brian Dickman).

Removed support for endpoint/pipe non-control interrupts; these did not act in the way users expected, and had many subtle issues.

Fixed RNDISEthernet not working under Linux due to Linux requiring an "optional" request which was unhandled.

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.