In the past, I've had trouble keeping the current set of version scripts
to correctly output the version, especially in light of how we append
Git suffixes for a non-tagged commit and dirty state. This change
replaces those scripts with a single Python one which, though much more
wordy than the previous one, may be easier for contributors to read and
modify. The original scripts relied on Perl; this one relies on Python,
which seems like a fair exchange. Having a single script also makes it
easier to solve #372.
Andrew Brown