Squish search for cadence jump piont.

Simplified the search for a cadence jump function.

File                             Raw         Min         Zip     Min/Zip
index.js                 10635/10.39  3588/03.50  3067/03.00  1382/01.35

File                             Raw         Min         Zip     Min/Zip
index.js                 10527/10.28  3390/03.31  3043/02.97  1319/01.29
Add a few comments to constructor functions.
String to indicate event handler.

Using a string type to indicate an event handler builder. The event
handler builder will invoke an event assignment method on a event
emitting object.

The string passed to step indicates the name of the function to invoke
on the event emitting object. It returns a function that can be used to
create arrayed or scalar event handlers. The function accepts a target
event emitting object and an event name.

Closes #63.
Closes #50.
Merge branch `events` into `master`.