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/Calendar.php b/system/libraries/Calendar.php
index 72d228e..df0fd6e 100644
--- a/system/libraries/Calendar.php
+++ b/system/libraries/Calendar.php
@@ -47,7 +47,7 @@
 	{
 		$this->CI =& get_instance();
 
-		if ( ! in_array('calendar_lang'.EXT, $this->CI->lang->is_loaded, TRUE))
+		if ( ! in_array('calendar_lang.php', $this->CI->lang->is_loaded, TRUE))
 		{
 			$this->CI->lang->load('calendar');
 		}