There are a range of subtle and irritating bugs that stem from
attempting to work with renames from the package set provided by cargo
metadata.

Fortunately, recent versions of cargo metadata provide a limited version
of the resolve nodes, both as the original node ids and as a newer set
providing both rename and targeting information.

As such we can (hopefully) simplify crate -> dep node resolution, remove
a bunch of subtle aliasing bugs.

Fixes #241, fixes #269, fixes #270, resolves #144, resolves #187