use jasmine clock instead of disabling trigger
use jasmine clock instead of disabling trigger

@kum-deepak, Jasmine has a neat way of advancing the clock for tests, which is better than disabling
dc.trigger with `EVENT_DELAY = 0` because it keeps the asynchrony. I forget how it works but it's
simpler than you'd think.

dc-js/dc.js,dc-js/dc.js,dc-js/dc.js,dc-js/dc.js,dc-js/dc.js