Replaces old serializers with new on time-line route.
Replaces old serializers with new in pubsub.
Removes redundant toJSON from models.
Replaces old serializers with new in tag synchronizer.
Adds info to anonymous.
Adds attachment serializer.
Post serializer strategy refactoring.
Feed info serializer refactoring.
Time-line serializer refactoring.
Fixes few typos.
Replaces old serializer invocation in groups model with new one.
Changes db migration to a right format 'date +%s%N | cut -b1-13'
Extracts admin serializer to separate file.