[BUGFIX beta] Add better debugging for DefaultResolver.

Adds nice log entries if your application was created with `LOG_RESOLVER` set.

Example log entries:

```
[ ] route:application ..........................................  App.ApplicationRoute
[✓] route:index ................................................  App.IndexRoute
[ ] controller:application .....................................  App.ApplicationController
```

Fixes #4654.

Example JSBin: http://emberjs.jsbin.com/maxum/1 (look at console)