[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
```
Merge pull request #4655 from rjackson/add-resolver-logging

[BUGFIX beta] Add better debugging for DefaultResolver.