OS Builder/Enable taptoclick

Tap to click has been disabled by request of many deployments. To enable it for ALPS, Synaptics, and AVC Touch-pads you must alter a few files:

For ALPS and Synaptics:

Modify the file /etc/modprobe.d/olpc-psmouse.conf changing to the option taptoclick=0 to taptoclick=1

For AVC:

Two files must be altered:

Editing the FSPPS/2 section of /lib/udev/olpc_mouse_setup and change the "c" to "C"
Editing a register value in /usr/bin/olpc-fsp-regs so the value for register 0x42 is 87.

Additional Note:
From AVC spec:
" 0x42 is the OPC register controlling tap to click (Disable=0xE7,Enabled=0x87)"