Support "org.apache.cordova.inappbrowser"

Requiring the npm module fails with "Cannot find module 'cordova/exec'".

Executing the exec command directly without requiring the JS plugin works however (atleast on Android):

``` javascript
var page = tabris.create("Page", {topLevel: true}).open();

tabris.create("Button", {text: "Open Google"}).on("select", function() {
var noop = function() {};
cordova.exec(noop, noop, "InAppBrowser", "open", ["http://google.com", "_system"]);
}).appendTo(page);
```

Using target "_self" and "_blank" also works, but the InAppBrowser's layout is broken and the keyboard doesn't open upon tapping on the current URL: