File upload and download support

Upload (POST), Download (GET), work in progress…containers next
Start of Container support

Containers!
Container and File integration work in progress
More file work.
Refactored some file and container methods
File/Container Unit Tests
Code cleanup

+ use Adapter.BinaryCallback for file download
Extract method AsyncTestCase.createRestAdapter
Extract class AsyncTask from AsyncTestCase.
Use Repository<T>, remove BeanUtil.

Use the recent improvements made in strong-remoting-android.
Add storage service to test-server.
Refactor Container to extend VirtualObject

Extract Model and ModelRepository callbacks to generic interfaces
that can be used with VirtualObject too.

Extract class RestRepository that adds REST contract to the Repository
from strong-remoting.

Refactor Container & ContainerRepository to inherit from VirtualObject
& RestRepository, since the Container "model" is not a DAO-based model
and does not support DAO methods like findById or update.
Default implentation of VoidTestCallback.onSuccess

Remove boilerplate code

    new VoidTestCallback() {
        @Override
        public void onSuccess() {
            notifyFinished();
        }
    }
Finish implementation of Container & File.

Clean up the code.
Add missing unit-tests.
Implement missing methods.
Remove code no longer used.
Remove TODO comments left over.
Merge pull request #28 from strongloop/feature/file-model

File model