Several fixes

Mostly compatibility across Python 2.6, 2.7 and 3.3. Enabled travis-ci.org automated commit testing. This is how it looks like for my clone: https://travis-ci.org/saschpe/Lesscpy. I can only recommend using it since it's also auto-testing pull requests to your repo. And you can have cool badges like here: https://github.com/saschpe/rapport/blob/master/README.rst

Hope you like it