Use a postgresql connection string instead of host/user/etc. variables
Cast explicitly to text to satisfy newer postgres/postgis
Use native bindings, so we can connect to Heroku via SSL
Log the pg connection string
Use recent pg module
Merge branch 'master' into heroku-pg
Merge branch 'master' into heroku-pg
Merge branch 'master' into heroku-pg

Conflicts:
	lib/postgres.js
Merge pull request #101 from LocalData/heroku-pg

Support Heroku Postgres