Response: Add contentType attribute

refs #12161

library/Icinga/Web/Response.php

@@ -54,6 +54,13 @@ class Response extends Zend_Controller_Response_Http
      */
     protected $rerenderLayout = false;
 
+    /**
+     * Content type of this response
+     *
+     * @var string
+     */
+    protected $contentType = 'text/html';
+
     /**
      * Get the auto-refresh interval
      *
@@ -205,6 +212,30 @@ class Response extends Zend_Controller_Response_Http
         return $this;
     }
 
+    /**
+     * Set the content type of this response
+     *
+     * @param  string $contentType
+     *
+     * @return $this
+     */
+    public function setContentType($contentType)
+    {
+        $this->contentType = $contentType;
+        return $this;
+    }
+
+    /**
+     * Get the content type of this response
+     *
+     * @return string
+     */
+    public function getContentType()
+    {
+        return $this->contentType;
+    }
+
+
     /**
      * Entry point for HTTP responses in JSON format
      *