Some misc dev cleanup

@semente @jaap3

Just some minor things here:

* Documentation and gitignore.
* I removed the tox tests for python 2.5 because they are no longer supported.  Proof below:

```
(smuggler)[peterconerly@django-smuggler]$ tox
GLOB sdist-make: /Users/peterconerly/code/django-smuggler/setup.py
py25-1.2 create: /Users/peterconerly/code/django-smuggler/.tox/py25-1.2
ERROR: UnsupportedInterpreter: python2.5 is not supported anymore, sorry
py25-1.3 create: /Users/peterconerly/code/django-smuggler/.tox/py25-1.3
ERROR: UnsupportedInterpreter: python2.5 is not supported anymore, sorry
```