Removing internal references to the EXT constant.  Additionally, marked the constant as deprecated.  Use ".php" instead. Also adding upgrade notes from 2.0.2 to 2.0.3.
diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php
index e5f6587..b30a8cf 100644
--- a/system/libraries/Encrypt.php
+++ b/system/libraries/Encrypt.php
@@ -524,7 +524,7 @@
 		{
 			if ( ! function_exists('mhash'))
 			{
-				require_once(BASEPATH.'libraries/Sha1'.EXT);
+				require_once(BASEPATH.'libraries/Sha1.php');
 				$SH = new CI_SHA;
 				return $SH->generate($str);
 			}