Install 2to3 script.

Misc/NEWS

@@ -160,6 +160,8 @@ Tests
 Build
 -----
 
+- A new script 2to3 is now installed, to run the 2.x to 3.x converter.
+
 - Python/memmove.c and Python/strerror.c have been removed; both functions are
   in the C89 standard library.
 

Tools/scripts/2to3

@@ -0,0 +1,5 @@
+#!/usr/bin/env python
+from lib2to3 import refactor
+import sys
+
+sys.exit(refactor.main())

setup.py

@@ -1716,6 +1716,7 @@ def main():
 
           # Scripts to install
           scripts = ['Tools/scripts/pydoc', 'Tools/scripts/idle',
+                     'Tools/scripts/2to3',
                      'Lib/smtpd.py']
         )