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/Log.php b/system/libraries/Log.php
index fb2c5a4..9f1db76 100644
--- a/system/libraries/Log.php
+++ b/system/libraries/Log.php
@@ -83,7 +83,7 @@
 			return FALSE;
 		}
 
-		$filepath = $this->_log_path.'log-'.date('Y-m-d').EXT;
+		$filepath = $this->_log_path.'log-'.date('Y-m-d').'.php';
 		$message  = '';
 
 		if ( ! file_exists($filepath))