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/helpers/html_helper.php b/system/helpers/html_helper.php
index a292043..080f622 100644
--- a/system/helpers/html_helper.php
+++ b/system/helpers/html_helper.php
@@ -259,13 +259,13 @@
 
 		if ( ! is_array($_doctypes))
 		{
-			if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/doctypes'.EXT))
+			if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/doctypes.php'))
 			{
-				include(APPPATH.'config/'.ENVIRONMENT.'/doctypes'.EXT);
+				include(APPPATH.'config/'.ENVIRONMENT.'/doctypes.php');
 			}
-			elseif (is_file(APPPATH.'config/doctypes'.EXT))
+			elseif (is_file(APPPATH.'config/doctypes.php'))
 			{
-				include(APPPATH.'config/doctypes'.EXT);
+				include(APPPATH.'config/doctypes.php');
 			}
 
 			if ( ! is_array($_doctypes))