These patches add support for newer tablets to the wacom w8001 serial
driver. The first patch simply adds the support for the Pen/Eraser tool and
the stylus button.

The second patch detects touch-capable tablets and discard their packets.
Touch packets are interleaved with pen packets and their length depends on
the sensor model. Detect these packets and discard them silently.

The third patch adds MT slot support for two-finger touch devices.

Patches tested on a 2 finger touch device but i've had positive confirmation
that 1 finger devices don't break.

Cheers,
  Peter