feat(daemon) `ipfs daemon --initialized`

With this PR, users can fetch and run ipfs in _one_ command.

```
docker run -d -p 4001:4001 -p 5001:5001 jbenet/go-ipfs daemon --initialized
```

Magic.

nb: needs https://github.com/jbenet/go-datastore/pull/9
Polite means it doesn't overwrite user-provided keys. By default, logrus will overwrite `time`, `msg`, and `level` with its own entries. 

documented in 9affbc44f0d9958cb8e0790493bbb6b4d211776e