show summary stats for all users

[geeksville]

A good idea from brandon:

Kevin--have you ever thought of putting a ticker somewhere, either user facing or just on a developer interface, that shows the total hours of flights logged and maybe some other macro analytics--could be really interesting to see, kind of like the analytics github shows.

(will need a small amount of backend goo)

[mrpollo]

+1 agreed this would be fun