declared $_filedata as static so it can work properly with recursion through subdirectories

http://codeigniter.com/bug_tracker/bug/6592/
diff --git a/system/helpers/file_helper.php b/system/helpers/file_helper.php
index 8078d96..b0c5546 100644
--- a/system/helpers/file_helper.php
+++ b/system/helpers/file_helper.php
@@ -223,7 +223,7 @@
 {
 	function get_dir_file_info($source_dir, $include_path = FALSE, $_recursion = FALSE)
 	{
-		$_filedata = array();
+		static $_filedata = array();
 		$relative_path = $source_dir;
 				
 		if ($fp = @opendir($source_dir))