Global settings

Adds a new service to define global application-wide settings.

The service can be configured through conf files in the main section, e.g.:

```
{
  "main" : {
    "globalSettings" : {
      "alwaysDeselect" : true
    }
  }
}
```

Currently there is only one possible global setting provided: The option to deselect tokens after every action. More will follow in subsequent Pull Requests, such as selecting the colorizer engine of tokens (right now only `morph` can do this, but we will allow `relation` to play a role here as well)

Code to handle later addition of such options is already in place. Right now the `navbar` holds a new button to trigger a panel where the settings can be adjusted on the fly.