Upgrade to setuptools, reorganize package to prevent from polluting virtualenv namespace

I found that utils.pyc kept getting inside my virtualenv such that ```import utils``` (a valid module name in a project of mine) was clashing with the utils.pyc in the top level.

Seeing that best practices for module packaging include placing said module into a subdirectory, I have moved the module logic into pytypedecl and left the unit tests/demo at the top level.

Features:
- You can now run ```python setup.py develop``` and effectively update code in the Git repo and have that be reflected on module imports outside the folder
- You can now run ```python setup.py test``` , which effectively allows for TDD and post-installation checks
- There is a basic MANIFEST.in suitable for source distributions and the appropriate package_data line added for a binary distribution on PyPI


Bugfixes:

- A nonexistent AST test was specified in all_tests.py --- it has been disabled
- Packages are supposed to use pkg_resource.* functions to retrieve module-specific data at run time instead of manipulating __file__ in an unsafe manner -- PyTypeDecl now does that (http://peak.telecommunity.com/DevCenter/PkgResources)

Requests:
- I'd like additional information on the error you encountered earlier with setuptools. Mind you, there is no 'help' command yet, but if that is all that is needed, I can easily add that.

Cheers,
Ben