- all inputs are now decoded as UTF-8, regardless of the platform
- decoding failures are now tolerated via transliteration given errant
  characters are generally expected to appear in comments

- use iverilog's -gstrict-expr-width throughout test suite
- add warnings for excess bits or padding zeroes in number literals
- add new --oversized-numbers parameter to retain support for unsized
  numbers wider than 32 bits
- localized use of oversized numbers to new truncate test suite which
  verifies the behavior of both modes, and compares against the known
  behavior of iverilog

In places where an optional space was previously allowed, allow any
number of arbitrary whitespace characters, in line with the spec and
other tools.

- preproc reads identifiers unconditionally
- drop leading whitespace for default macro args
- very minor preproc cleanup

- number literals are parsed rather than stored as strings
- fix array query functions used on non-trivial number literals
- more efficient expression simplification recursion
- expanded constant folding scenarios

- adds support for using macros and macro arguments within the argument
  list to other macros
- fixes an issue where macros with arguments would have extraneous
  whitespace
- fixes handling of multiline string literals