Fixing action command when using object with Regex values, readme example and syntax error.

1 - As you can see: https://wiki.asterisk.org/wiki/display/AST/Asterisk+11+ManagerAction_Hangup
The hangup action has regex support on "channel" attribute so instead of inform the entire channel name I can just inform a regex that matches to the channel name like this:
```javascript
  AMI.action({
      'action':'hangup',
      'channel': /^SIP\/9138-.*$/,
      'cause': '1'
  }, function(err, res) {
      console.log(err, res);
  });
```
Looking at your original implementation you're handling regex values assuming that is a ```key -> value``` object. ```typeof /regex/``` is an object but it holds a different constructor (RegExp).  So what I did was... inside of your conditional if who looks for an object I'm also checking if ```nval``` has an instance of RegExp and now the hangup command works like a charm.

2 - And I also tried to make the code I little more readable.
3 - there is syntax error in your README.md
4 - there is a invalid attribute on your example in your README.md