Packaged up rst2wp

Hello again,

I packaged up rst2wp so that it can be installed using:
```
python setup.py install
```
and used wherever one is (less messing around with symlinks).

It works for me right now, but I certainly haven't tested everything. So let me know if I can improve anything. (I really did this to learn how to package so...)

Also you can fill out the meta-information and maybe it can eventually be put up on pypi so that others can use this great tool easily through pip install.

Thanks!