Add support for HTTP basic access authentication.

With Webdis it is possible to define some access control rules to allow or
disallow certain commands and one of the possible configurations is based on
plain old HTTP authentication.

lib/Predis/Network/WebdisConnection.php

@@ -118,11 +118,23 @@ class WebdisConnection implements IConnectionSingle {
         }
     }
 
+    protected function getHttpOptions() {
+        $options = null;
+        if (isset($this->_parameters->user, $this->_parameters->pass)) {
+            $parameters = $this->_parameters;
+            $options = array(
+                'httpauth' => "{$parameters->user}:{$parameters->pass}",
+                'httpauthtype' => HTTP_AUTH_BASIC,
+            );
+        }
+        return $options;
+    }
+
     public function executeCommand(ICommand $command) {
         $commandId = $this->getCommandId($command);
         $arguments = implode('/', array_map('urlencode', $command->getArguments()));
 
-        $request = new HttpRequest($this->_webdisUrl, HttpRequest::METH_POST);
+        $request = new HttpRequest($this->_webdisUrl, HttpRequest::METH_POST, $this->getHttpOptions());
         $request->setBody("$commandId/$arguments.raw");
         $request->send();