Rename from list-processing -> serial

So it makes obvious what particular property of asynchronicity the scenario is all about.

--HG--
rename : scenarios/list-processing/async.js => scenarios/serial/async.js
rename : scenarios/list-processing/callbacks.js => scenarios/serial/callbacks.js
rename : scenarios/list-processing/co.js => scenarios/serial/co.js
rename : scenarios/list-processing/deferred.js => scenarios/serial/deferred.js
rename : scenarios/list-processing/pinky-sync.js => scenarios/serial/pinky-sync.js
rename : scenarios/list-processing/pinky.js => scenarios/serial/pinky.js
rename : scenarios/list-processing/promises.js => scenarios/serial/promises.js
rename : scenarios/list-processing/q.js => scenarios/serial/q.js
rename : scenarios/list-processing/when.js => scenarios/serial/when.js