Mouse & NKRO support

Hi Ben,

I was able to add NKRO and mouse support to your firmware based on hasu's firmware and the following thread:  http://geekhack.org/index.php?topic=13162.msg259955#msg259955

Currently I use 24 byte long reports (it can include all the keycodes between 0 and 192; the 16 byte version doesn't include some keypad keys), and works fine (on linux at least, I have no access to OSX or Windows).

The code could be better organized, but lately you were quite busy as well, and I didn't want to wait until you do some great refactoring :)

Regards,
  Gyuri