improve caching smb results a bit

apps/files_external/lib/smb.php

@@ -60,6 +60,10 @@ class OC_FileStorage_SMB extends OC_FileStorage_StreamWrapper{
 		}
 	}
 
+	public function filetype($path){
+		return (bool)$this->opendir($path);//using opendir causes the same amount of requests and caches the content of the folder in one go
+	}
+
 	/**
 	 * check if a file or folder has been updated since $time
 	 * @param int $time