Support for injecting into arbitrary objects

Injection can now be performed for Activities (same as before): 
```java
public class MainActivity extends ActionBarActivity {
  @InjectList(R.id.list) AbstractViewAdapter<Account> adapter;

  @Override protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    AbstractViewAdapter.injectAdapters(this);
    //TODO use adapter to add items to the list
  }
}  
```
and for arbitrary objects, for example a fragment: 
```java
public class ListFragment extends Fragment {
  @InjectList(R.id.list) AbstractViewAdapter<Account> abstractViewAdapter;

  View rootView;

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    rootView = inflater.inflate(R.layout.fragment_list, null);

    AbstractViewAdapter.injectAdapters(this, rootView);
    //TODO use adapter to add items to the list

    return rootView;
  }
}
```

Note that root View object should be passed as well in this case.