Fix the issues with cx_Freeze builds on newer versions of python and
with newer version of PyQt5
- Update .gitignore to ignore .spec files
- Update package.py to use pyInstaller instead of cx_Freeze
- Update requirements-windows to have pyInstaller instead of cx_Freeze
- Update setup.nsi to work with build and packaging changes
- Add win_version_info.temp to build a version information file for
pyInstaller as part of the package.py script
