Restore Plone 4.3. support

Do not merge yet.

@thet Almost there. I opened this pull for discussion.

All tests run on Plone 4.3 with correct other versions. I should document them soon. Plone 4.3 compat portlet templates are still missing.

@datakurre that's of course a good point. but how does it do that? the profile has a different name (bbb).