Replace "in a few seconds" with more accurate time

[joeframbach]

Agendash currently uses e.g., moment(1458000000000).fromNow() to display the time difference for last execution and next execution. When a job is within 45 seconds of executing, moment will display in a few seconds which is not very helpful and is not very configurable.

Replace moment.fromNow with something better.

[joeframbach]

I tried attaching the jquery timeago plugin to each $el on render. I must've done something wrong because I had memory leaks everywhere. After a minute the tab was using 650MB.