Put sort object into a service.
Refactored Stats.

* separate stats/statCollection services.
* calculate only the stats that are presently displayed.
* separate filtered/raw stats to avoid re-calculation each time the filter is (de)activated.
* re-calculate stats only when battles/filter change.
Implemented partial battle list display.
Inject sort_types in sort instance.
Collapse navbar on small screens.
Added Cyriss icon.
Extracted all show flags from stats collections.
Added stats percents.

closes #6
Implemented filter inversion.

closes #17