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/index.php b/index.php
index 6e67c2d..a8d58b2 100644
--- a/index.php
+++ b/index.php
@@ -163,6 +163,7 @@
 	define('SELF', pathinfo(__FILE__, PATHINFO_BASENAME));
 
 	// The PHP file extension
+	// this global constant is deprecated.
 	define('EXT', '.php');
 
 	// Path to the system folder
@@ -198,7 +199,7 @@
  * And away we go...
  *
  */
-require_once BASEPATH.'core/CodeIgniter'.EXT;
+require_once BASEPATH.'core/CodeIgniter.php';
 
 /* End of file index.php */
 /* Location: ./index.php */
\ No newline at end of file