Unit stack rebalancing rework

- CStackInstance::count is now private with accessor methods
- CStackInstance::experience renamed to totalExperience and now stores
total stack experience (multiplied by stack size) to reduce rounding
errors
- CStackInstance::totalExperience is now private with accessors methods
- stack experience is now automatically reallocated on stack management
- Removed buggy BulkSmartRebalanceStacks pack, that mostly duplicates
BulkRebalanceStacks
- Renamed BulkSmartSplitStack to BulkSplitAndRebalanceStack to drop
unclear "smart" in name
- Reworked split-and-rebalance logic to correctly reallocate stack
experience

lib/gameState/CGameState.cpp

@@ -1304,7 +1304,7 @@ bool CGameState::checkForVictory(const PlayerColor & player, const EventConditio
 				{
 					for(const auto & elem : ai->Slots()) //iterate through army
 						if(elem.second->getId() == condition.objectType.as<CreatureID>()) //it's searched creature
-							total += elem.second->count;
+							total += elem.second->getCount();
 				}
 			}
 			return total >= condition.value;