lxml/lxml — pull request #30 by lrowe (2012-02-07 14:30:14+00:00)
Title: Use regexp for cssselect ":contains()" pseudo-class

This provides:

* portability with other xslt processors
* removes the 'css' global prefix assignment which can cause unexpected behaviour when working with xml files using that prefix
* a slight performance improvement

Users now need to explicitly pass in the regexp namespace when calling the ``xpath()`` method if they use the deprecated ``:contains()`` pseudo-class.