Master master into letsencrypt-auto-release so Travis will build it.

docs/using.rst

@@ -139,9 +139,20 @@ Would obtain a single certificate for all of those names, using the
 ``/var/www/example`` webroot directory for the first two, and
 ``/var/www/eg`` for the second two.
 
+The webroot plugin works by creating a temporary file for each of your requested
+domains in ``${webroot-path}/.well-known/acme-challenge``. Then the Let's
+Encrypt validation server makes HTTP requests to validate that the DNS for each
+requested domain resolves to the server running letsencrypt. An example request
+made to your web server would look like:
+
+::
+
+    66.133.109.36 - - [05/Jan/2016:20:11:24 -0500] "GET /.well-known/acme-challenge/HGr8U1IeTW4kY_Z6UIyaakzOkyQgPr_7ArlLgtZE8SX HTTP/1.1" 200 87 "-" "Mozilla/5.0 (compatible; Let's Encrypt validation server; +https://www.letsencrypt.org)"
+
 Note that to use the webroot plugin, your server must be configured to serve
 files from hidden directories.
 
+
 Manual
 ------
 
@@ -237,7 +248,9 @@ The following files are available:
   server certificate, i.e. root and intermediate certificates only.
 
   This is what Apache < 2.4.8 needs for `SSLCertificateChainFile
-  <https://httpd.apache.org/docs/2.4/mod/mod_ssl.html#sslcertificatechainfile>`_.
+  <https://httpd.apache.org/docs/2.4/mod/mod_ssl.html#sslcertificatechainfile>`_,
+  and what nginx >= 1.3.7 needs for `ssl_trusted_certificate
+  <http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_trusted_certificate>`_.
 
 ``fullchain.pem``
   All certificates, **including** server certificate. This is