R1:7c934e41764f

Add a basic "fact" application

Summary:
Basic "Fact" application with some storage, part of a daemon, and a control binary.

= Goals =

The general idea is that we have various statistics we'd like to compute, like the frequency of image macros, reviewer responsiveness, task close rates, etc. Computing these on page load is expensive and messy. By building an ETL pipeline and running it in a daemon, we can precompute statistics and just pull them out of "stats" tables.

One way to do this is just to…