Remove u'' syntax that is unsupported in Py 3.2.

Include a very basic tox.ini file to run the test suite against multiple
versions of Python.

The removal of the u'' syntax is in line with the fact that Python 3 strings are unicode by default.

@ikirudennis, I found that Python 2.7 and Python 3.2 tests were broken so I figured this branch would help make things a little better. You mentioned being 'n00b' so here's some extra explanation to help you out with what I did. Sorry if this is overly pedantic. I try to assume people have minimal knowledge even at the risk of repeating myself or boring you with stuff you already know.

In a nutshell, I gave developer's the ability to quickly test against other versions of Python if those versions are installed on their machines. `tox` is the tool that makes that possible. My Ubuntu 14.04 machine has Python 2.7, 3.2, 3.3, and 3.4 installed on it. Here is a quick list of commands you could run to get a flavor for this (assuming you have the same versions installed).

```bash
$ virtualenv ~/venv
$ source ~/venv/bin/activate
(venv) $ cd python-textile
(venv) $ python setup.py develop
(venv) $ tox -e py27
(venv) $ tox -e py33
(venv) $ tox -e py34
```
1.   virtualenv lets you create an environment to install stuff without using sudo (i.e. everything you install goes into the virtual environment instead).
2.   Activate the virtualenv.
3.   Install `tox` via the setup.py file
4.   Run `tox` on various versions of Python

If all this stuff is goodness for you, I can eventually show you how to integrate this with Travis CI (https://travis-ci.org/). Travis CI would then monitor the repo and run the tests for **all** the versions automatically each time a commit happens to master. Additionally, each pull request would have the Travis build results showing whether tests passed or failed before you even review it. I think that's very useful. Hopefully you do too.

I'd be happy to do some more on the branch (like adding the initial Travis file) if that's of interest to you.