Add in method to build manifest URL.

Author: pingevt

src/Iiif/IiifImage.php

@@ -19,6 +19,13 @@ class IiifImage extends IiifBase {
    */
   protected $thumbHeight = 200;
 
+  /**
+   * Build the full manifest URL.
+   */
+  public function getManifestUrl() {
+    return implode("/", [$this->server, $this->prefix, $this->iiifId, "info.json"]);
+  }
+
   /**
    *
    */