* Add gossipsub and ping
* Implement swarm key parsing from environment
* WIP remove stuff
* WIP remove more stuff
* Use gossipsub instead of floodsub
* Make ipfs example work with or without swarm key
* Add support for /ipfs/Qm1234 multiaddrs
* Add documentation for ipfs example
* Rename example to ipfs-private
* Fix comments
* Move EitherTransport into either.rs
And prettify imports of ipfs-private example
* Sanitize multiaddr before parsing
...and remove the "ipfs" protocol from multiaddr
* Remove TSubstream type parameter
...so that it works with current master
* PR feedback
use source instead of cause
