added constants.php file and implemented constants for file system modes
diff --git a/system/codeigniter/CodeIgniter.php b/system/codeigniter/CodeIgniter.php
index 866be35..04936b9 100644
--- a/system/codeigniter/CodeIgniter.php
+++ b/system/codeigniter/CodeIgniter.php
@@ -43,7 +43,14 @@
  * ------------------------------------------------------

  */

 require(BASEPATH.'codeigniter/Compat'.EXT);

-	

+

+/*

+ * ------------------------------------------------------

+ *  Load the compatibility override functions

+ * ------------------------------------------------------

+ */

+require(APPPATH.'config/constants'.EXT);

+

 /*

  * ------------------------------------------------------

  *  Define a custom error handler so we can log PHP errors

diff --git a/system/codeigniter/Common.php b/system/codeigniter/Common.php
index d9ddf80..4554a71 100644
--- a/system/codeigniter/Common.php
+++ b/system/codeigniter/Common.php
@@ -52,7 +52,7 @@
 		}

 		

 		fclose($fp);

-		@chmod($file, 0777);

+		@chmod($file, DIR_WRITE_MODE);

 		@unlink($file);

 		return TRUE;

 	}