Linting, typo corrections, general code cleanup

Though there remain two function-based views (parks.parks_page and parks.park_ajax) that seem to be stale.
Adding nearby and recommended parks to base park response payload
Ensure vagrant setup includes libjpeg-dev for PIL purposes
Add images to park recommendations
Merge branch 'master' of github.com:mjacksonw/bostongreenmap
Merge pull request #54 from mjacksonw/master

Adding nearby and recommended parks to park JSON payload