Thanks Carl Meyer for review.

Fixed definition of `klass_info['from_parent']` so that two models aren't
considered from a parent class if the model classes are the same.

Thanks Tim for the review.

Restored the behavior before 727d7ce6.

Thanks Mariusz Felisiak for finishing the patch.

https://bugs.python.org/issue23722

Thanks Nick Coghlan for advice and review.

Cells in the first column must contain some text.
http://docutils.sourceforge.net/docs/dev/rst/problems.html#tables

PROJ.4 4.7.0 was released on 25 Sep 2009 and is available in Ubuntu 12.04.

Removed DatabaseFeatures.supports_bitwise_or feature (unused, always True).