devnotes.rst: better PyPI build/upload step

This way I can not have my PyPI password sitting in plaintext in my
home directory!
pwkit/cli.py: add unicode_stdio()
pwkit/pdm.py: import Phase Dispersion Minimization implementation
pwkit/astutil.py: import
Update a few copyright lines.
pwkit/casautil.py: import
pwkit/astimage.py: import