Flexible necromancy (#430)

* made IMPROVED_NECROMANCY bonus configurable
* updated cloak of the undead king

lib/ResourceSet.cpp

@@ -13,6 +13,8 @@
 #include "StringConstants.h"
 #include "JsonNode.h"
 #include "serializer/JsonSerializeFormat.h"
+#include "VCMI_Lib.h"
+#include "mapObjects/CObjectHandler.h"
 
 Res::ResourceSet::ResourceSet()
 {
@@ -86,6 +88,14 @@ bool Res::canAfford(const ResourceSet &res, const ResourceSet &price)
 	return true;
 }
 
+TResourceCap Res::ResourceSet::marketValue() const
+{
+	TResourceCap total = 0;
+	for(int i = 0; i < GameConstants::RESOURCE_QUANTITY; i++)
+		total += static_cast<TResourceCap>(VLC->objh->resVals[i]) * static_cast<TResourceCap>(operator[](i));
+	return total;
+}
+
 std::string Res::ResourceSet::toString() const
 {
 	std::ostringstream out;