Eager loading associations for Pois, speed up.

- By using eager_load instead of includes, AR is able to almost
  eliminate extra queries. This shaves of roughly 2/3rds of the
  full request time on the nodes/index.geojson query.
- Made a specific method on Pois for the eager load. Not too sure abt
  method name…
- disconfigured librato to disable librato debug messages in development
- added a few annoying things to .gitignore