- new net decl to replace net pseudo-type
- support nets with complex base types, including typenames
- support var declaration type prefix for all data types
- support var as lone type shorthand
- refactor AST representation of strengths
- traversal helpers for treating nets as variables
- use decl traversals where appropriate

- 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

- elaborated literals larger than 32 bits are given an explicit size
- constant folding no longer encodes illegal negative numbers

- removed repetition in dimension query conversion
- removed repetition in package item nesting conversion
- packing item nesting conversion short circuit
- param type conversion doesn't bother renaming non-param type instances
- implement showsPrec for certain expression cases

- single bit localparams retain explicit range
- fix $bits on unsized literals
- use Implicit over Maybe for underlying type