Normalize Event Position

If the AwesomeMap is disabled after a touch, but before a release,
then it will continue to emit InteractionEvents. However, the position
of these events will be relative to the window, not the viewport
hosting the AwesomeMap. Normalize the event positions to ensure
predictability in client code.

Unit Tests
-------------

- Cover normalization

How To +10/QA
-------------

```bash
# skip the following steps if you've already initialized the project
$ git clone git@github.com:WebFilings/wf-uicomponents.git
$ cd wf-

# do not skip these!
$ git fetch && 
git checkout normalize_event_position && 
./init.sh && 
grunt qa
```

- Should see no console errors.
- All tests should pass

@lancefisher-wf 
@patkujawa-wf 
@georgelesica-wf