Add some extra PS/2 mouse command constants
Initial changes for ALPS V3 touchpad

Some cleanup still needed...
Changes to xcode for VoodooPS2 base
Rework of code base for ALPS V3 touchpad support and more extensible touchpad support

- Factor out a bunch of common stuff into a VoodooPS2TouchPadBase class
- Factor out the decay logic stuff into a separate include
- Also includes better implementation of the ALPS driver for V3 with
multi-touch scrolling, better trackstick support, middle click with the
trackstick buttons, smoother movement, etc.
Modify utilities to allow for ALPS touchpad as well as the synaptics one

Basically just look for the ALPS driver as well as the Synaptics one
Make the ALPS trackpad be able to use the built in trackpad pref pane

- The scroll tables might still need some work...no idea if some of the
settings actually work