fix last seen

fix last seen using AuthService's promise which retrieves userProfile
switch to filtered collections

- use filtered collections pattern similar to broadcast controller
- add show all button
add number of activities and bugfix

changed objectLength filter to differentiate between object and array
because otherwise number returned may be 3 higher than correct (the
functions in an angularFireCollection are counted - not desirable)
bugfix and cosmetic change
replace local time with server time and add todos
Store the full name into the profile
remove unnecessary code
switch from filteredActivities object to array
Merge pull request #9 from reebalazs/activity_stream2

Activity stream improvements
fix merge conflicts