Issue #2212149: Improve task queue AJAX refresh. Progress in implementing Vue.js.

 - Adding content type to Hosting Task View and template so it reads "Verify Site:" instead of "Verify".
 - Adding jQuery "timeago" plugin  and adding timestamps so we can dynamically update "time ago". See http://timeago.yarp.com/
 - Styling "time ago" text to not be too obtrusive.