[type-graph] update for new inheritance relations, japhb++
[type-graph.txt] remove Seq. It is probably gone for good.
[type-graph.txt] remove IO::Dir and IO::File
[type-graph.txt] fix up entries for Stash and Signature
[type graph] fix for roles with superclasses
also remove some more non-spec types
[type-graph] remove Rakduo-specific stuff