ignore sublime files
add unique key for subscriptions (check, user, method)
only process checks once per cycle, not once per subscription per cycle
get correct count for alerts - makes pagination work on homepage
add newline to processor debug statement
handle null values in check processing
skip processing of checks with missing or null values
use mutex for processing
order alerts on homepage by timestamp (latest first)
Merge branch 'master' of github.com:matthew-lucidchart/Graphite-Tattle

These changes should allow for Tattle to scale better, and fixes:
- only process checks once per cycle (adds a unique key for subscription)
- handle and skip null values in processor
- order alerts