Overhaul of thread handling to support blocking functions other than wait

luprex/core/cpp/util.hpp

@@ -212,9 +212,6 @@ eng::string toupper(eng::string input);
 // Calculate distance between two points
 double distance_squared(double x1, double y1, double x2, double y2);
 
-// Return true if a world type is authoritative.
-bool world_type_authoritative(util::WorldType wt);
-
 // Make a LuaSourceVec with one element, for unit testing.
 LuaSourcePtr make_lua_source(const eng::string &code);