add doubletap2wake, completely rewritten on the s2w template

This is as easy to port as s2w, if not easier since no touchscreen
coords are necessary for it to work.

Just throw it in your tree, force the touchscreen to stay online and
you are done.

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
s2w: abort on multitouch events early

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
dt2w: fix triple tap to wake occuring sometimes

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>