Fix when is 'self' used as a parameter name in Python

Fix corner case for variable names called 'self' after merging in patch #201

Examples/test-suite/keyword_rename.i

@@ -35,6 +35,10 @@ KW(chan, fallthrough)
 KW(end, function)
 KW(nil,local)
 
+struct Keywords {
+  void selfkw(int self) {}
+};
+
 %}
 
 

Examples/test-suite/python/keyword_rename_runme.py

@@ -1,4 +1,6 @@
-#!/usr/bin/env python
 import keyword_rename
 keyword_rename._in(1)
 keyword_rename._except(1)
+
+k = keyword_rename.Keywords()
+k.selfkw(123)

Lib/python/pythonkw.swg

@@ -130,7 +130,7 @@ PYTHONKW(None);
 /* 
    'self' is also a bad Name
 */
-PYTHONBN(self);
+PYTHONKW(self);
 
 #undef PYTHONBN
 #undef PYTHONKW