Fix host/hostname confusion.

Introduced in 0.8.0, diagnosed in Automattic#66 (comment).

lib/client.js

@@ -267,16 +267,16 @@ var Client = module.exports = exports = function Client(options) {
  */
 
 Client.prototype.request = function(method, filename, headers){
-  var options = { hostname: this.endpoint, agent: this.agent }
+  var options = { hostname: this.host, agent: this.agent }
     , date = new Date
     , headers = headers || {}
     , fixedFilename = encodeSpecialCharacters(ensureLeadingSlash(filename));
 
   // Default headers
-  utils.merge(headers, {
-      Date: date.toUTCString()
-    , Host: this.host
-  });
+  headers.Date = date.toUTCString()
+  if (this.style === 'virtualHosted') {
+    headers.Host = this.host;
+  }
 
   if ('undefined' != typeof this.token)
     headers['x-amz-security-token'] = this.token;