Start implementing unified data loader.
Finish data loader logic and integrate 'aggergatedData' service to it.
Display current time, last update time and loading status on nav bar.
Use data loader for follow ups table.
Set reload delay back to 5min.
Integrate map data management into data loader.
Enhance data loading state display.
Merge pull request #95 from hbj/feature/last_update_time

Unify data loading and display update time. Fixes #11.