Simplify udev rules

[mgrouch]

I think all you need instead of all current udev rules is:

SUBSYSTEMS=="input", KERNEL=="event[0-9]*", ENV{ID_INPUT_TOUCHSCREEN}=="1", SYMLINK+="touchscreen0"
SUBSYSTEMS=="input", KERNEL=="event[0-9]*", ENV{ID_INPUT_TOUCHSCREEN}=="1", SYMLINK+="twofingtouch", RUN+="/bin/chmod a+r /dev/twofingtouch"