The Perl/CPAN dependency system is organized around versions for each Perl
module/package, rather than versions for each distribution. Up until now, we
have only maintained a version in Lucy.pm; in order to accommodate Perl/CPAN,
we must make a version available for every public Perl module.
The solution is to add an explicit version number to each Perl package which
is visible to CPAN. To reduce errors, version numbers will be modified using
the devel/bin/update_version script, and the Perl build system will validate
versions for all published modules when building the CPAN tarball.
Additionally, we will require a more recent version of Module::Build when
building the CPAN tarball. (The fact that the CPAN release of Lucy 0.3.0 was
built with an earlier version of M::B than 0.2.2 caused problems related to
this version numbering issue.)