Implement new `cid(blob, ...)`

[vmx]

The IPLD Format spec was changed so that util.cid() now takes the binary blob and not the deserialized DAG Node as argument (#24).

This is a breaking change and needs to be done on all existing formats. So please don't merge before PRs from all formats are approved. This way things can be merged and released in one go.

Instead of opening an issue on every repository, just let people know on this issue that you're working on it and then link to the PR.

• https://github.com/ipld/js-ipld-bitcoin
• https://github.com/ipld/js-ipld-dag-cbor
• https://github.com/ipld/js-ipld-dag-pb
• https://github.com/ipld/js-ipld-ethereum
• https://github.com/ipld/js-ipld-git
• https://github.com/ipld/js-ipld-raw
• https://github.com/ipld/js-ipld-zcash