Started work on serialization.
Added serialize() prototypes to the other classes.
Did work on string serialization.
Did work on serialization of non-printing or non-ASCII characters.
Finished string serialization.

The library compiles again!
Implemented DsonArray serialization.
Implemented DsonObject serialization.
Implemented DsonNumber serialization.
Found a test that libDSON failed.

Will merge into main, then investigate.
Merge branch 'serialization'