Change #! line to modern usage

Demo/pdist/rcsbump

-#!/usr/local/bin/python
+#!/usr/bin/env python
 # -*- python -*-
 #
 # guido's version, from rcsbump,v 1.2 1995/06/22 21:27:27 bwarsaw Exp

Demo/pdist/rcvs

-#! /usr/local/bin/python
+#!/usr/bin/env python
 
 import addpack
 addpack.addpack('/home/guido/src/python/Demo/pdist')

Demo/pdist/rrcs

-#! /usr/local/bin/python
+#!/usr/bin/env python
 
 import addpack
 addpack.addpack('/home/guido/src/python/Demo/pdist')