Adding new capabilities to startApp in android adb, updating adb.startApp in appium, adding a test and updating package.json,caps.md and appium-adb submodule. 

-Related to #2026
-Added new capabilities intentAction, intentCategory, intentFlags, optionalIntentArguments and defaulting them. 
-Added new test to launch activity with a category
-Updated caps.md
-Made sure that adb.startApp is called with object which all properties corresponding to appium-adb 1.1.0
-updated package.json 
-updated submodule commit to point to new minor of appium-adb.
hmm, let's not call this callback, since we already have a callback in this function. Let's call it `next`, or `onStart`. Also, I think the interface should actually be changed again :-/. I don't think `cb` should be part of the options. I think it should be the second param, e.g., the signature of `startApp` should look like:

```js
var startApp = function (opts, cb) {
...
};
```

Since this is the convention in Node. Unfortunately, this means changing appium-adb again! Sorry I didn't catch this in that review.