Implement a stats gen_server
Add an event source API for the stats
Update the stats when forwarding chunks
Implement the UI for front page stats
Add new counters

  - total-data-transfer becomes total-data
  - total-files
  - total-uploads
  - average-size
Improve the css of the stat section
Move the total-files counter to be more accurate
Merge branch 'feature/real-time-stats' into develop