Feature Request :: programmatic support for named profiles

I can programmatically start and stop profiling using constructions like this:

```
agent.loadedAgents["Profiler"].start({}, () ->)
```

The v8-profiler [`startProfiling` function](https://github.com/c4milo/node-webkit-agent/blob/master/lib/v8-profiler.js#L212) supports providing a name for a profile, but the [Profiler `start` function](https://github.com/c4milo/node-webkit-agent/blob/master/lib/profiler.js#L153) doesn't provide a way to pass a name to `startProfiling`. I'd like to be able to do

```
agent.loadedAgents["Profiler"].start({name: "my-profile-name"}, () ->)
```

and have that name passed along.