testtools no longer works on py3k

Since r45 a there has been a relative import in testtools.testresult which apparently breaks the package under Python 3.

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "testtools\__init__.py", line 24, in <module>
    from testtools.runtest import (
  File "testtools\runtest.py", line 12, in <module>
    from testtools.testresult import ExtendedToOriginalDecorator
  File "testtools\testresult\__init__.py", line 13, in <module>
    from real import (
ImportError: No module named real