0.2.3 released

Written for testresources by Robert Collins on 2010-01-24

* Distribute doc/*.py in the source tarball.

* New helper testresources.GenericResource which should remove the need for
 much boilerplate when using testresources with existing test fixtures.

* New public functions testresources.setUpResources and
  testresources.tearDownResources for folk that cannot easily use
  ResourcedTestCase. Fixes bug #504146.