manually include vc runtime in windows package

ensure USAGE.txt is included in sdist and wheel

fix script entry guard - ignore errors if stdio does not exist

fix mac packaging script for latest cx_freeze

Merge packaging fixes

update linux package names to python3-*

update metadata

bump version to 2.0.3

packaging: ensure dlls are not included in mac and linux packages

ensure that release.json gets installed and pythonw gui script gets i…

…ncluded in wheels