Implement audio capture API

Please visit the following url to run the test MIDlet:
`http://localhost:8000/index.html?jars=tests/tests.jar&midletClassName=org.mozilla.AudioRecorder`

you can set the pref `media.navigator.permission.disabled` to `true` to disable the permission prompt.
I'd move all the code that uses player.audioRecorder from the natives in AudioRecorder and make PlayerContainer a proxy for those calls, for example:

    PlayerContainer.prototype.getRecordedSize = function() {
        return this.player.getRecordedSize();
    }

    AudioRecorder.prototype.getRecorderSize = function() {
        return this.data.byteLength;
    }

This will make it easier to implement other *Recorder classes and would be easier to read as all the logic would be in the same class (AudioRecorder).

(I haven't added the check for a null player in PlayerContainer::getRecorderSize, you can add it if it's actually needed to throw an IllegalStateException, otherwise a NullPointerException will be thrown)