Adds additional configuration options for NGINX

I needed to add SSL client authentication and a few other options for an application I'm working on. This adds the ability to specify client auth, as well as any generic directive into the location declaration.
This seems independent of the SSL client verification change.  Could you post a separate PR for the `LOCATION_OPTIONS` change?   TBH, I'm hesitant to merge `LOCATION_OPTIONS` change as there are some other ideas floating around for customizing templates that have not been fully explored yet.