improve activity stream user display

- add link to private chat from activity stream userid
- add full name display for activity stream userid
only show full name if available
add full name display to broadcast stream
eliminate ng-if and Object.keys

- ng-if not supported in Angular stable (switched to ng-show)
- Object.keys not support le IE9
no instances of these remain in project
Merge pull request #14 from reebalazs/improve_streams

Improve streams