Fix 3k's sphinx-build.py so that the version detection works with 2.x and 3.x.
diff --git a/Doc/tools/sphinx-build.py b/Doc/tools/sphinx-build.py
index d72a831..e87b6c0 100644
--- a/Doc/tools/sphinx-build.py
+++ b/Doc/tools/sphinx-build.py
@@ -12,12 +12,12 @@
 if __name__ == '__main__':
 
     if sys.version_info[:3] < (2, 4, 0):
-        print("""\
+        sys.stderr.write("""\
 Error: Sphinx needs to be executed with Python 2.4 or newer (not 3.0 though).
 (If you run this from the Makefile, you can set the PYTHON variable
 to the path of an alternative interpreter executable, e.g.,
 ``make html PYTHON=python2.5``).
-""", file=sys.stderr)
+""")
         sys.exit(1)
 
     from sphinx import main