Various fixes to Elasticsearch configuration

- It's now possible to specify http auth paramters in the URL
- I've changed the default port to 443 to SSL connections and 80 for
  non-SSL connections. Previously, both were set to 9200.

The second change was motivated by the fact that searchly don't specify a port in their URLs when they actually want users to connect to port 443. Also, I think it makes sense for a HTTP URL to default to ports 80 and 443, even though they're most commonly going to be pointing at port 9200.