pylint tests: Save .pylintrc in .pylintrc.bak in case something bad happens and it can't be restored.

(integrated from komodo (trunk) change 83385 by ericp)

git-svn-id: http://svn.openkomodo.com/repos/openkomodo/trunk@14106 b87d16e7-d29f-4ee1-b5ec-817d645d335f