- entirely new PackedArray conversion (always flattens)
- typedef and struct correctly order packed ranges when combining types
- Stmt LHS traversal no longer traverses nested statements to avoid double conversion
- Logic conversion applies to `initial` blocks`
- new and modified tests to cover these cases

- added support for macros with default arguments
- fixed bug where nested preprocessor conditionals would not be skipped
- macro expansion respects escaped quotation marks
- macro expansion considers whole identifiers, rather than substituting in wildly

This also entailed further fleshing out the expression traversal helper
to cover expressions in generate blocks, which could, of course, use
$bits.

- convert default pattern used to fill a vector
- convert Logic in parameter and localparam types
- interface conversion should happen early for type resolution later on
- interface conversion handles renaming of usages of inlined decls