basic ID cmd

The ID command I implemented here doesnt have all the information that @jbenet mentioned he would like to have in #228, I wasnt sure how to access the version information without using the config (we wont be able to get configs from remote peers)
nono let's not do this because we dont want to have to compute it every time. We could move to this:

```Go
	if p.pubKey == nil && p.privKey != nil {
		p.pubKey = p.privKey.GetPublic()
	}
	return p.pubKey
```
but did you actually fall into this case?