SmallyMouse2 Firmware Release v1.1

This is the second release of the SmallyMouse2 firmware and is intended for further testing against a wider range of retro computers (primary testing has been against Acorn 8-bit and 32-bit computers). The release zip contains the compiled AVR AT90USB1278 firmware in both HEX and ELF formats (for programming using the DFU FLIP bootloader over USB).

This release fixes a couple of minor issues from v1.0 (see the issue tracker for details)