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

client/UIHelper.cpp

@@ -50,10 +50,10 @@ soundBase::soundID UIHelper::getNecromancyInfoWindowSound()
 std::string UIHelper::getNecromancyInfoWindowText(const CStackBasicDescriptor & stack)
 {
     MetaString text;
-    if(stack.count > 1) // Practicing the dark arts of necromancy, ... (plural)
+    if(stack.getCount() > 1) // Practicing the dark arts of necromancy, ... (plural)
     {
         text.appendLocalString(EMetaText::GENERAL_TXT, 145);
-        text.replaceNumber(stack.count);
+        text.replaceNumber(stack.getCount());
     }
     else // Practicing the dark arts of necromancy, ... (singular)
     {