Remove dependency on ordereddict if sys.version_info > (2,7)
Change unicode string to fix build on Python 3.2.
Simplify ordereddict requires (see discussion in pull req #27).
Changelog update.

[ci skip]
Merge pull request #28 from mcmtroffaes/feature/ordereddict-only-py26

Remove ordereddict dependency for Python 2.7 and higher.