Links for defusedxml

http://en.wikipedia.org/wiki/Billion_laughs
http://en.wikipedia.org/wiki/Document_Type_Definition
http://www.python.org/psf/license
https://www.isecpartners.com/media/12976/iSEC-HILL-Attacking-XML-Security-bh07.pdf
mailto:brett@python.org
mailto:christian@python.org
http://msdn.microsoft.com/en-us/magazine/ee335713.aspx
https://en.wikipedia.org/wiki/Processing_Instruction
http://en.wikipedia.org/wiki/Zip_bomb