-modified references to CHANGES and README from '.txt' to '.md'

-added testing for python 3.3 and 3.4 in tox config

-refactored code so as to pass existing unit tests in python 3.3-3.4 environment. (no further test created)
- merged https://github.com/JDeVos/wsgicors.git python3x_support
- moved from markdown to reST, to ease pypi / github hosting
Merge branch 'python3'
bump version for pypi release