sort .gitignore
git ignore buildout.cfg
Fix standard buildout for testing.

Use buildout.plonetest from github.
Add zope.app.component and zope.app.container because contentratings needs it.
Should be fixed there and released.
Fix getting field values.
Fix errors getting portal_syndication, which may not be available.
Replace product_icon.gif with product_icon.png.
Remove tests.py.  We have a tests directory.
Fix test for file_size of downloadablefile.

The getObjSize script in CMFPlone changed kB to KB.
See https://dev.plone.org/ticket/12567