Feature Request: add a --follow option that will recursively build missing dependencies.

[jnbek]

Sometimes, modules like Redis, Moose, Catalyst::Runtime add a new dependency that doesn't yet exist on AUR and that one dependency has a rabbit hole of upwards of 10-15 new dependencies, none of which exist on AUR. I wonder how difficult it'd be to add a --follow arg that will find missing deps and fire off a build for those as well. Obviously, this might also catch new dependencies that already exist on AUR, but that's easy enough to deal with... I was thinking that we could pull in WWW::AUR to search, for said existence or not.... but... I'm thinking that we should keep this CPANPLUS plugin with as few dependencies as possible... perhaps... the WWW::AUR search code could be made a separate plugin to this plugin. --follow would be implemented in cpan2aur and perhaps a hash key for the new() instantiation.