Extension:E3 Experiments/Architecture

mw:Extension:ClickTracking loads the right files in ResourceLoader by globbing experiment/*.js used by various extensions besides E3, like moodbar, article feedback tracking.

Timing
JavaScript code on client computes experiment start and end times, eligibility duration, etc.
 * test: use latest dashboard (see ../Testing, it reports times. ? See if bucketing occurs inside/outside the window.