Make an activity for given owner from given all activities
Create newsfeed-activity value that represents a single post for given date and owner
Fix activiity on group-profile
Using 'swap' instead 'update' to set a new value of group activity
Dont rely on owner property to set value of compound entity
Move activit-loader to own file
Implement atom protocol for activity-loader to deliver loaded activities
Save an activity to local storage
Add only activity that is not loaded before
Set visible groups in main-layout state