Display dates in timeago format

Add angular-momentjs to dependencies

Update all date fields to include am-time-ago tag, to properly display dates

Configure that using UTC timezone according to API requirements
Timeago will be shown for changes done in less than one week, displaying
a tooltip with whole date on hover.
Full UTC date will be displayed for older changes.

Change-Id: I2f4c1facaa3a99808f89900dbeb6b6cacb31f8a6
Closes-Bug: 118