Added native app voice trigger intent so you can say "OK, Glass, start launchy"

![device-2013-06-01-113924](https://f.cloud.github.com/assets/704768/595219/1766a4a2-caeb-11e2-920a-15bdf8d372b7.png)
This only works with devices that has the lab NATIVE_APP_VOICE enabled, see https://gist.github.com/zhuowei/5624527 I tested it with a Nexus 7 running the Xenologer APKs.

see #5 for previous discussion.