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.
diff --git a/Tools/scripts/sum5.py b/Tools/scripts/sum5.py
index 3efcc74..4250dde 100755
--- a/Tools/scripts/sum5.py
+++ b/Tools/scripts/sum5.py
@@ -16,7 +16,6 @@
 """ % bufsize
 
 import sys
-import string
 import os
 import md5
 import regsub
@@ -89,7 +88,7 @@
         if o == '-t':
             rmode = 'r'
         if o == '-s':
-            bufsize = string.atoi(a)
+            bufsize = int(a)
     if not args: args = ['-']
     return sum(args, out)