Upload support

This pull request introduces upload support. It does not come with documentation, as that will be part of a later pull request. If you wish to test uploading an archive: find any Python package, and run it's setup.py with the sdist argument. It will output a tarball, and you should be able to upload that to Pulp. To verify that it's been uploaded, you should be able to see it in Mongo like this:

```
> db.units_python_package.find()
```

Also, you should find the package you uploaded stored in ```/var/lib/pulp/content/python_package/```.
On 10/23/2014 03:43 PM, bmbouter wrote:
> How is this different than the two tests just above it? It seems those
> covered the good metadata both at the root and nested in a subfolder? Is
> this test necessary? I see one difference is PKG-INFO does not have a
> slash at the front, but since that is a relative path isn't that
> technically the root still?

tarchives can have relative or absolute paths in them, so that leading /
is the difference between these tests. Really we are testing that the
regex matches the file correctly. I should probably consider using
os.path to do that instead of a regex, now that I think about it…=