child containers inherit type injections

This PR makes type injections inherit to sub-containers. Setting *new* type injections on child containers are still prevented. Reasoning below:

We would like to use the store and router inside of our controls. For instance, we currently have code such as the following:

```
{{view GT.HeaderView controllerBinding="controllers.header"}}
```

And instead would like to use:

```
{{control header}}
```

However, the header controller logic requires access to the store/router.