Test suite broken on Python 2.4 by RunTest changes

[Martin Packman]

Trying to run the test suite then fails with:

Traceback (most recent call last):
  File "testtools\run.py", line 280, in ?
    program = TestProgram(argv=sys.argv, testRunner=runner)
  File "testtools\run.py", line 133, in __init__
    self.parseArgs(argv)
  File "testtools\run.py", line 188, in parseArgs
    self.createTests()
  File "testtools\run.py", line 197, in createTests
    self.module)
  File "C:\Python24\lib\unittest.py", line 556, in loadTestsFromNames
    suites = [self.loadTestsFromName(name, module) for name in names]
  File "C:\Python24\lib\unittest.py", line 524, in loadTestsFromName
    module = __import__('.'.join(parts_copy))
  File "...\testtools\tests\__init__.py", line 6, in ?
    from testtools.tests import (
  File "...\testtools\tests\__init__.py", line 6, in ?
    from testtools.tests import (
  File "...\testtools\tests\test_runtest.py", line 5, in ?
    from functools import wraps
ImportError: No module named functools

From the changes for bug 657760, and as can be seen at:
<http://docs.python.org/library/functools.html>
Module is 2.5 and later only.