Implement Cawdor as new Medieva game

[ZaneDubya]

Whereas the code for Yserbius and Twinion can only run Yserbius style games (and even more specifically, only Yserbius and Twinion), Cawdor runs on a new client/server dungeon crawler engine that is somewhat more generic than the yserbius/twinion specific code that is currently found in the game. This issue will track two things: First, how generic should the new engine be, and second, what yserbius-specific systems must be written to support the new engine. .... this will be a work in progress ....

To evaluate:

Reviewed systems, already generic

• Server Achievements - generic, but I got rid of the achievement bootstrapping, which was not generic.
• Server Automaps - generic, generated by client
• Server BattleSystem - generic.
• Server Guilds, Partying - generic
• Server Treasure tables/picking - generic
• Server Gallery - only 6 slots, otherwise generic. I'm leaving this as is because of the shared names feature.
• Server ChallengeSystem - generic.

Server, may retain Yserbius specific code for Cawdor:

• Entities, Player - Yserbius focused - but NEED NOT REWRITE FOR CAWDOR?!
• Entities, Monster - Yserbius focused.
• Battle - Yserbius focused. This is stateful code and would be difficult to properly rewrite ... and then keep in sync with the original :(

Server, must make generic:

• KeepSystem - mostly generic, but will need to
  • remove references to original game's template items...
  • and bank expand costs are hardcoded in the bank code. I might need to make this a separate system.
• Buffs - Yserbius focused. Must rewrite. Make MobileBuffCollection generic #1008
• Entities, Item - Must rewrite and then do an in-place database upgrade. Replace all YsItem with LegacyItem; YsItemTemplated replaced with data prototypes. #1009
• Maps - Want new CwMap class, inherits from LegacyMap.
• World - Yserbius focused, but easy to rewrite.?
  • Make YsWorld the core Yserbius/Twinion world type, inheriting from AWorld.
  • Make CwWorld a separate world type, using Cawdor graphics but else
• SmsgBattleRound - Yserbius focused.
• SpellMethods/SkillMethods/SpellArgs - must be completely rewritten with generic ability use class.

Client, mostly generic.

• Will need to rewrite GameIDs, ModeEditChar, YsAppearanceData and FaceRenderers, SubmodeCombat, identity strings, ability use check, and the tooltip generator for buffs. Most of this will be easy.
• What might be difficult is all the UI elements!
• ClientState - done

[ZaneDubya]

First major issue discovered: the WorldMedieva items are (of course!) only fancy yserbius items. Same attributes, same classes allowed field, same protection types.