Add the ability for styx to attach CORS headers

This change adds a new routing rule that handles CORS headers.  It also incorporates a new version of http-proxy which doesn't have a resource leak bug in it.  Yay?

Lastly, I pushed up dependency versions and switched everything to use amoeba instead of the local files.
databased is not a word
Merge pull request #2 from tidepool-org/cheddar/add-cors

Add the ability for styx to attach CORS headers