* UDEV registers touch pad (e.g., Synaptic) with different IDs on
reboots. Instead of hard-coding product/device IDs in config.h,
use a string that appears in device name to identify it
* Added function toggle_touch_input_device to toggle enaled state of
touch device.
* This function is called in key bindings.
* Touch device is identified by vendor/device id provided in config.h
