Add CLI command to send command to any speaker by name

Right now this requires a full topology scan every time, which may be fast or slow depending on your network and the number of devices. I have 2 speakers and it's pretty fast. Larger networks could benefit from caching mentioned in #2.

This also literally uses the `send()` function so you can do stuff like

``` bash
sonos speaker Office volume= 25
```

Not sure if this is a good or bad idea :smile:

If your speaker name has a space in it, of course you'll have to do:

``` bash
sonos speaker "Living Room" pause
```