Initial implementation

[aschmahmann]

Some TODO items to make things more usable:

• [x] Convention for returning errors
• [ ] Build step for stripping compiled wasm modules
• [x] Document WASM interface for various pieces
  • [x] Codec Encode
  • [x] Codec Decode
  • [x] ADL Bytes
• [x] Link to go-ipfs fork/branch that handles WASM Codecs + ADLs (https://github.com/aschmahmann/go-ipfs/tree/fun/wasm)
• [x] Switch block loading extern function to send data back as WAC and/or raw blocks rather than just raw blocks

Related TODOs:

• [ ] WAC spec proposal + review
  • May include related data model conversations around the fun topics of strings, map keys and floats 🙃
• [ ] Bencode spec
• [ ] BitTorrent filev1 ADL spec
  • Figure out if I've done it correctly and look at what the v1 directory and v2 file specs would be like as contrast
• [x] Would be cool to demonstrate ADL Maps using BitTorrent v1 directories