Generate the version number automatically.

Signed-off-by: Jason Lynch <jason@calindora.com>
Create a wrapper script to handle the build process.

This allows us to move automatic version generation out of the tup process,
which allows us to get around the fact that tup might otherwise miss certain
instances (e.g. after a commit) when the version information should be
regenerated.

Signed-off-by: Jason Lynch <jason@calindora.com>