Added reliance on version.pm, which means we should deal much
better with the wide range of version specifications one finds on
CPAN. This is made possible by recent releases of version.pm that
give the user a pure-perl option, so installing version.pm
shouldn't be too onerous for most users. [John Peacock]We should be accepting the default when we're in unattended mode,
not acting dumb and ignoring both the default and the [empty]
answer from the user. Fixed. [Spotted by Nik Clayton]