update todo
add support for double-tap and drag
update todo
remove some un-used commented code for handling left/right margins
fix a bug in the computation of average movement.
had to do with signed/unsigned division.
convert all remaining useful printfs to DPRINTFN
remove couple of obsolete todo items
check on all sc_state transitions and flags.
delete un-necessary flag: ATP_VALID
add a comment for not checking interface_protocol in probe()
update todo
introduce atp_slide_min_movement to convert to slides