Record more information in the dex file

Include all constants and types used in the dex file.
Fix the type parser to be reusable for method signature strings

It was calling endOfInput to make sure we didn't have trailing garbage,
but that made it hard to re-use.  Lifted the endOfInput calls to a
higher level.
Add two useful helpers for inspecting Methods
Resolve direct method references in invokes when possible

This was originally the intent, but some metadata was not correctly
being updated.
Add an SSA-flavored class hierarchy analysis