- avoid premature conversion of default struct type parameters
- allow use of $clog2, $signed, and $unsigned in type parameters
- more thorough and efficient top reference ident renaming
- precede type param conversion with hier const pass

- renaming applies to nodes within generate blocks
- renaming applies to LHSs

- remove -o/--oneunit, has been the default behavior
- revise test coverage for default vs. siloed behavior
- add test to ensure README usage matches CLI help text
- remove -V alias for --version
- remove -? alias for --help

- wait for hierarchical references within an instance's type parameters
  to be resolved before instantiating the module
- references to a module's top-level named scopes are now correctly
  renamed when creating new type parameter modules