Syntax error.
StringIO Py3.
Py3 all the prints!
Eliminate zope.app.testing import.
Py3 all the StringIOs!
Avoid zope.app.testing by setting up our own placeless and placeful setup.
Get rid of zope.app.schema dependency.
One more use of zope.app.testing.setup.
Handle bytes or unicode depending on Python version.
More import changes.
Fix syntax.
Exec syntax.
More Py3 porting.
Py3 fixes: mostly StringIO imports.
More Py3 test fixes.