Add OrderedDict backport for Python 2.6

The OrderedDict class was added in Python 2.7. This adds an OrderedDict
class based on a Raymond Hettinger recipe for use on Python 2.6.
http://code.activestate.com/recipes/576693/
Make compatible with Python2.6 syntax

Handle differences in syntax between Python2.6 and later Python version.
Address missing dictionary comprehensions, missing implicit string
formatting positions and missing OrderedDict class.
Configure continuous integration with Travis-CI

Adds the Travis-CI YAML configuration file to control continuous
integration tests.