add modelines to .hxx files as well

autodoc/source/parser/cpp/pe_enum.hxx

@@ -1,3 +1,4 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /*************************************************************************
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -136,3 +137,4 @@ PE_Enum::Result_FirstNameSegment() const
 
 #endif
 
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */