User requested features & bug fixes

* When cycling through castle HUDs, show correct castle faction art (thanks @dasara III!) * Dead units stay on battle screen, easier to review battle results (thanks @dasara III!) * Removed an incorrect entry in the Tome re: terrain strength hotkey * Added unlisted keyboard hotkeys to Tome entry * Fixed bug where an explored ruin, in an unexplored region of the minimap showed up as a neutral castle icon. * Fixed battle issue where sometimes a unit with zero HP would survive More & bigger updates will be coming in Q4!