0.12.0

This introduces breaking changes as the default behavior for stringify has slightly changed:

• Enums will be serialized to their textual representation
• u8 slices will be serialized to byte strings
• For structs and unions:
  • null fields are skipped by default
  • fields of type std.mem.Allocator are always skipped.
  • the names of fields are serialized to text strings (you have to explicitly tell stringify to treat the name of a field as integer)

Also, stringify and parse now use the same Options.