Originate_Context doesn't work with Asterisk 11

```
python code like this:

manager = pystrix.ami.Manager()
callinfo = pystrix.ami.core.Originate_Context(
        "SIP/001@127.0.0.1:5060","callout","1","1"
        )
manager.send_action(callinfo)

I think that it due to ast11 has new arguments of Originate such as EarlyMedia.
```

Original issue reported on code.google.com by `lxit...@gmail.com` on 17 Apr 2013 at 6:39
