Create a component mixin to format elapsed time (e.g. 4 mins ago)

[ntad2]

Create a component mixin to format a JavaScript Date as a string stating the time elapsed. E.g. 1 minute ago, 1 hour ago, 1 day ago, 1 month ago, 1 year ago.

Use the Vue mixin.

Use it for the Messages Page issue #46 and #48 (and possibly elsewhere too).