Plone.app.testing

------------------

- Add 'ROBOT_TEST_LEVEL' to interfaces, so other packages can import it. This
makes things easier if we decide to change the value.
[timo]

- Replace deprecated test assert statements.
[timo]

- plonetheme.classic no longer ships with Plone, don't use it for
testing.
[esteele]

- Clean up the zodbDB and configurationContext resources if there
is an error during the PloneSandboxLayer setUp.
[davisagli]

- Make PLONE_FIXTURE not install a content type system.
Packages that need content types to run their tests should
pick the appropriate fixture from plone.app.contenttypes
or Products.ATContentTypes.
[davisagli]

- Pin [robot] extra to ``robotsuite>=1.4.0``.
[saily]

- Fix wrong spelling of ``reinstallProducts`` method in quickInstallProduct.
[saily]

- Sync bbb PloneTestCase class with original one.
[tomgross]

------------------

- Add [robot] extras for requiring dependnecies for Robot Framework
tests with Selenium2Library
[datakurre]

- Install PythonScripts as zope product
[mikejmets]

------------------

- Allow testing with non standard port. Allows running multiple test suites
in parallel.
[do3cc]

- Documentation updates.
[moo]

----------------

- Branch as 4.2 as the plone.app.collection addition breaks backwards
compatibility.
[esteele]

- Fixed spurious failure in our own tests by using a longer timeout.
[maurits]

- plone.app.collection added to PloneFixture.
[timo]

------------------

- Load ZCML before installing Zope products in ``PloneWithPackageLayer``;
it enables package registration.
[gotcha]

------------------

- Add ``additional_z2_products`` parameter to ``PloneWithPackageLayer``
helper class to install additional Zope 2 products.
[jfroche]