Fix Windows compilation errors

- On Windows, Visual Studio 2008 Express Edition fails to find `tre-config.h`. This pull request provides a copy of it in the appropriate location.
- On Windows, there's no `setup.py` file; only the `setup.py.in` template is provided. The pull request provides an template-replaced version of `setup.py`.
- On Windows, `tre.dll` is placed in `C;\Pythonxy` along with a warning. This pull request places it in the `site-packages` directory alongside of `tre.pyd`.