Cleans up the unit tests that are meant to be run with nosetests

* Renames all test modules to start with test_ so that nosetests does
not need to be run with the --all-modules flag in order to pick them up
* Renames test_helper to fakes and removes imports in unit tests that
did not reference the fakes
* Adds nose to pip-requires so that run_tests.sh -V will install nose
into the virtualenv instead of having to manually install it after running
into import errors :)

tools/pip-requires

@@ -20,3 +20,4 @@ zope.interface==3.6.1
 mox==0.5.0
 -f http://pymox.googlecode.com/files/mox-0.5.0.tar.gz
 greenlet==0.3.1
+nose