Make "helo" and "test" packet use new command format

```
The helo packet should transmit its contents in a data structure similar to the 
one used for results:

{ 'command' => 'helo', 'data' => { ... } }

That would simplify the serializers, possibly dropping the need to have the 
serializers tell the daemon that they "need a helo to work".

```

Original issue reported on code.google.com by `pplusdom...@gmail.com` on 12 Jan 2011 at 11:43
