Revert "Temp. remove express api mock server because of compile problems"

This reverts commit 67535d41efdabcfff5c054940be4825f87352736.
Mock vmstat api
Move app/assets/api to api-mock
Remove jquery-timeago from bower because of compile issues
Add jquery.timeago.js manually
More realistic vmstat
Add volumes.json mock
Improve vmstat.json with NICs etc
Add volumes index + list ctrl
Remove unnecessary comma
Add Volume by id view
Enhanced api mock server, serving all + by_id calls
Serve mock volume by_id
Add groups.json
Remove linebreak
Add user list view
Add user detail view
Enhance user mocking
Fix group mock data