TouchWake implementation v1.4b (Yank555.lu)

- finger and pen working
- call detection working through proximity sensor detection
- use of wakelock is optional (sysfs switchable)
- fixed for CM11 ROMs
- reviewed digitizer handling

What's new :

- don't use proxy sensor state when suspending to decide whether or not to enable touchwake & small fixes

SysFs interface :

* /sys/class/misc/touchwake/enabled (rw) : 1 - on / 0 - off
*
* Enable / Disable TouchWake (default = disabled)
*
* NB: Turning the device off with the power key will disable touchwake
*
* /sys/class/misc/touchwake/delay (rw) :
*
* Sets the delay in ms to keep touchscreen / pen actively listening for touch after screen goes off
*
* NB: A value of 0 equals "infinite", will drain battery !
*
* /sys/class/misc/touchwake/proximity_threshold (rw) :
*
* Sets the threshold from which to consider the proximity sensor triggered (which will disable touchwake)
*
* NB: This serves as a kind of in-call detection to not turn the screen on during a call when placing
* the device to the ear
*
* /sys/class/misc/touchwake/use_wakelock (rw) : 1 - on / 0 - off
*
* Enable / Disable using a wakelock to keep device awake while TouchWake is active (default = enabled)
*
* /sys/class/misc/touchwake/version (ro) :
*
* Display the current version of TouchWake
*
* /sys/class/misc/touchwake/debug (ro) :
*
* Display debugging info (only if debugging is active at compilation time)