Add new detection method which simply searches for zero-crossings
Add new detection method which simply searches for zero-crossings

Unlike other methods, only needs to inspect 1 element in either
direction, making it the fastest method by nearly 2x.

Similar properties to -m orig; fairly conservative, but with few
false positives. Works best with normal scale factors (< 4x).

0x09/resdet,0x09/resdet,0x09/resdet,0x09/resdet