Dont magically add "current/public" to root-path.

When deploying a rack app, or deploying with capistrano, you can still
add that to the root path instead.
Use site_root as variable for pointing to root.
Set index and autoindex variables
Merge branch 'feature/path' into develop

* feature/path:
  Set index and autoindex variables
  Use site_root as variable for pointing to root.
  Dont magically add "current/public" to root-path.
Update documentation to capture intention of site_root
use File.join to avoid double slashes