1) spell handler refactored to support modding in general way
2) imunnity icons moved to WoG as they depends on wog`s graphics
3) introduced new class template for handlers (todo: use this in other handlers)
4) save format changed
5) introduced "absolute immunity" - unaffected by "the Orb" etc. (todo: use it in config)
6) new format documented on wiki, added json schema.
* more split of registertypes - fixes 32 mingw build
- WoG should be optional, all remapped files are listed in WoG/config/wogFileOverrides.json
- fixed several cases of incorrect positioning of creatures in battles
- some missing sounds for battle effects
- negative luck support, disabled by default
- a bit hackish detection of WoG presence, VCMI should work on SoD-only installs
- town screen is mostly implemented, has some minor issues
- factions are now separate from towns, neutrals have faction with id=9
- more constants to GameConstants: town-specific buildings, strings for terrains and resources
- replaced most access to builtBuildings with isBuilt() method
- replaced id's with enums for town subtype and buildings id's
