this isn't right.
moving stats work to async, adding user count to stats page
some feedback from @brianloveswords
moved user total count into the model, added a test
moved badge statistics to badge model, added a test
rebase, plus the fixes for #491
changed the way the doc bits are in there, using return...like a boss
forgot a return
Merge pull request #546 from cmcavoy/498-record-number-users

498 record number users in /stats page

[closes #498]
[closes #491]