Consistently pass peer name along with on_peer_* calls

See issue https://github.com/z25/pyZOCP/issues/31
This patch adds "name" as an argument to the zocp callbacks so they match the pyre callbacks. 

To be discussed: 
```on_modified``` is the only callback where the order is data, peer, name. In the other callbacks, the order is peer, name, data. This is because ```on_modified``` can also be used without a peer (and name) if the node has modified itself. In those cases, perhaps zocp should "fill in the blanks" and provide ```self``` and ```self.name``` to the callback?