T/nginx optimization

Adds the following:

 * support for multiple php-fpm pools on a single instance
 * support for the same in nginx
 * shorter timeouts between nginx and php-fpm
 * nginx settings like epoll, more worker connections, auto-select of available cores and accept multiple
 * tests for the pool configuration and setup

@till No idea either :) However, we do have `node['deploy'][appname]['document_root']` in opsworks for that, and `node['vagrant']['applications'][appname]['doc_root_location']`in vagrant, guess one of those makes sense. There is a small difference between those two, the vagrant one has the full path, the opsworks one only the relative, like "www".