Style listnavigator better

res/static/script/Viewer.js

@@ -18,6 +18,12 @@ var Viewer = {
 			Toolbar.toggle();
 		}
 
+		// The close button only works if the window has an opener. So we hide
+		// the button if it does not
+		if (window.opener === null) {
+			$("#button_close_file_viewer").remove();
+		}
+
 		if(type === "file"){
 			this.isFile = true;
 			this.currentFile = data.id;