Properly use setuptools

I never thought of hid-tools as something that would be properly packaged in distributions.

But I guess people might want it, so maybe it's time to have a proper setup.py so we can ship parse_hid.py in distributions

TODO list:

• move everything into a hidtools package directory
• move the commandline bits into the respective modules (hid/replay.py, hid/parse.py)
• setup.py with the console_scripts entries