Predefined data and loader created
1. Date format changed to RFC3339.
2. "_id" fields removed from the ActivityStreams predefined data.
3. Activity Stream object changed accordingly with the document http://tools.ietf.org/html/draft-snell-activitystreams-09
4. Small UI optimizations.
Merge pull request #2 from maksim-marholin/master

Predefined data and loader created