Cleaned up file persistence (separated all IO stuff into a separate trait) and added what will become our HTML templates.
Unrefined implementation of export to schedule-detail file.

 Outstanding issues:
 - export of brief files
 - country still needs to be separated out (probably introduce yet another template fragment)
 - Scheduler is ugly: needs to be broken up into a bunch ov val components and assembled together in one place, instead of defining everything and their mother inline
Moved character escaping to exporter
- taught schedule to list countries where events take place and events by country
- renamed ScheduleEntry to Event
- some cleanup
- Broke down events by country in HTML export
- cleaned up resources
Prep for event brief pages support
Implemented brief pages export. Only UI beautification is remaining!
Merge branch 'feature/json2hmtl' into develop