Refactor test_functional to use plone.app.testing.
Refactor test_install to use plone.app.testing.
Refactor doctests to use plone.app.testing.
Drop Products.PloneTestCase and collective.testcaselayer.
testing: tear down workaround so that we can run PloneTestCase and p.a.testing in the same process.
Merge pull request #8 from plone/jone-eliminate-plonetestcase

Use plone.app.testing