Added an import fallback for xml.etree.ElementTree.ParseError.

This error class does not work on Python 2.6, at least not with
AOC's current set of libraries. The fallback is to use
xml.parsers.expat.ExpatError, which is what the lib raises on
2.6.
Bumped the version number a tiny bit.
Merge branch 'master' of github.com:operasoftware/oex2nex

* 'master' of github.com:operasoftware/oex2nex:
  Update README.md