Test

Markus,

Here is some start to add proper automated testing.
We can not just

cd tests
make

and it will run all the tests for cdb and unmarshalling we have on the current code in the repository.
This will let us test the changes before we do  'python setup.py install'

(
We should probably expand this to also add tests for example the enums    but we need to re-work the existing test_enum.py a little before we can do that.
)