- Add support for new features in YubiKey 2.2.
    - Stricter argument parsing, to help user avoid configuration surprises.
    - Ask kernel to detach USB HID driver with libusb 0.1 too.
    - Properly reject keys (-a) with upper case hex, instead of just ignoring
      those bits.
    - Really check Yubikey compatibility when setting options.
    - Pretty-printer did not handle bit overloaded cfgflags.
      It is better now, but not perfect.
    - Fixes to make it work under Windows.