Changes to SSL and SPDY

Made SPDY a toggle param as requested by Issue #73. 

Also added ssl_ciphers and ssl_protocols as params which default to values as proposed here http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_ciphers and here: http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_protocols

If SSL vhost then ssl is added to listen directive as proposed here: http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl