take a dependency tree generated my npmd-resolve and convert it suitable for npmd-link
can also be used as a unix tool.
npm install -g npmd-resolve npmd-leaves npmd-resolve request | npmd-leaves | npmd-link
npmd-leaves transforms a npmd-resolve tree into leaf-first order
(topological sort). Every subtree is uniquely identified by the hash of it's
tarball + it's dependencies hashes.
it's used with npmd-link to do a module install based on symlinked dependencies.