Routing

Following the recent conf tweaks (#55), some additional changes to routing:

Predefined conf files are now stored in `app/static/configs/*.json`.
They are used when the app with started with the `conf` param, which can also be set through route matching.
To retrieve the `staging` configuration file you can therefore use:
- _app/staging_ (or even _app/#/staging_)
- _app/#/?conf=staging_ - note the hashtag inserted by angular needed for non HTML5 browsers.

Direct paths to conf files can still be given through a param:
- _app/#/?conf_file=URI_TO_FILE_

Starting the app without any params automatically redirects to the default configuration.