Support Asynchronous Datastores

fix: limit SW registration to content root

chore(dep): update go-libp2p

* Fixes a panic on close/write race in the websocket transport (https://github.com/libp2p/go-libp2p-kad-dht/pull/422)
* Fixes recursive resolution of dnsaddrs (for bootstrapping).

Introduces hardening proposed in:
https://github.com/ipfs/go-ipfs/issues/4025#issuecomment-342250616

License: MIT
Signed-off-by: Marcin Rataj <lidel@lidel.org>

update documentation for /ipfs -> /p2p multiaddr switch

See: https://github.com/libp2p/libp2p/issues/79

* fixes #6434
* switches the default libp2p multiaddr format to /p2p/Qm...

chore(dep): update a few deps

IPNS over PubSub as an Independent Transport

docs: add information on how to enable experiments

Change Reporter to BandwidthCounter in IpfsNode

update go-datastore

This was failing in CI.

chore: update readme badges to test ci

testing out circleci build triggers with a PR that tidies up the README badges

- remove somewhat redundant `project: ipfs` badge so they fit on 1 line. The link to the website is the url field for the repo.
- Use shields.io "flat square" style for godoc badge to match the others
- Use shields.io for the circleci badge too.
- re-order to be more visually pleasing.

License: MIT
Signed-off-by: Oli Evans <oli@tableflip.io>

Let's get this in so the datastore changes don't block other PRs.

chore(dep): update libp2p

Otherwise, we have port conflicts and other issues.