* Add emulated stick values for Nunchuk and Classic Controller
* Add acceleration sensor data to KPADStatus
I have also changed the posValid type from uint8_t to int8_t because the value can be negative.
A negative value means that the result validity is not really good.
* Set version to beta in the doc
* Added mask for button C and button Z on the Nunchuk
The same mask applies to WPADButton and WPADNunchukButton.
* Add doxygen comments and fix typos
Most of the comments are pretty obvious but at least it's a start.
* Fix a copy-paste error in my last commit
I have also added comments for VPADGetTPCalibrationParam and VPADSetTPCalibrationParam.
* Add documentation for all buttons
