Move module init code to own function
Move module init code to own function

This makes the code a little cleaner. The main reason for it,
however, is Python 2 and 3 have a different function protocol.
So early returns need to be aware of this. Putting everything in
a function that returns void makes this easier to deal with.
indygreg/python-zstandard,terrelln/python-zstandard,terrelln/python-zstandard,indygreg/python-zstandard,terrelln/python-zstandard,indygreg/python-zstandard,terrelln/python-zstandard,indygreg/python-zstandard