cpp: enums allow runtime introspection of names and values
xsd-fu: Reindent C++ enum template
build: Use ISO-8601 release date and also add UNIX date

This makes the string machine parseable and the unix date
may also be used directly where needed.  Switch the use of
regex parsing of "git show" output with direct use of
"git log".
cpp: Add version header
cpp: Add bioformats Version module