Apply diff2.txt from SF patch http://www.python.org/sf/572113

(with one small bugfix in bgen/bgen/scantools.py)

This replaces string module functions with string methods
for the stuff in the Tools directory. Several uses of
string.letters etc. are still remaining.

Tools/scripts/untabify.py

@@ -4,7 +4,6 @@
 
 import os
 import sys
-import string
 import getopt
 
 def main():
@@ -32,7 +31,7 @@ def process(file, tabsize):
     except IOError, msg:
         print "%s: I/O error: %s" % (`file`, str(msg))
         return
-    newtext = string.expandtabs(text, tabsize)
+    newtext = text.expandtabs(tabsize)
     if newtext == text:
         return
     backup = file + "~"