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/User_agent.php b/system/libraries/User_agent.php
index 04cda73..016102a 100644
--- a/system/libraries/User_agent.php
+++ b/system/libraries/User_agent.php
@@ -84,13 +84,13 @@
 	 */
 	private function _load_agent_file()
 	{
-		if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/user_agents'.EXT))
+		if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/user_agents.php'))
 		{
-			include(APPPATH.'config/'.ENVIRONMENT.'/user_agents'.EXT);
+			include(APPPATH.'config/'.ENVIRONMENT.'/user_agents.php');
 		}
-		elseif (is_file(APPPATH.'config/user_agents'.EXT))
+		elseif (is_file(APPPATH.'config/user_agents.php'))
 		{
-			include(APPPATH.'config/user_agents'.EXT);
+			include(APPPATH.'config/user_agents.php');
 		}
 		else
 		{