Packaging: Figure out how to make PyPi installs on Windows work

[omerk]

pip install llama-bsl on Windows works, but issuing "llama-bsl" on the command line doesn't run the script.

[omerk]

Relevant: https://docs.python.org/3/using/windows.html#python-launcher-for-windows (thanks @mattvenn!)

As far as I can tell, adding the ".py" extension back on the script and relying on the py launcher seems to work?

More testing needed

[omerk]

This is now fixed with the addition of console_scripts in setup.py