Players can no longer unilaterally use items on themselves in their inventory. When they try to use an item, they send a PlayerItemUse packet to the server with the item's details. A serverside script can then check the item and either send the packet back to make the item use go through or drop it.
Spell, potion, enchantment, creature, NPC, armor, book, clothing, miscellaneous and weapon record data can now be sent in a RecordDynamic packet. Additionally, the packets include data related to associated magical effects (for spells, potions and enchantments), data related to default inventory contents (for creatures and NPCs) and data related to body parts affected (for armor and clothing).
The server now has associated script functions for setting most of the details of the above, with the main exception being individual creature and NPC stats.
Records can either be created entirely from scratch or can use an existing record (set via the baseId variable) as a starting point for their values. In the latter case, only the values that are specifically set override the starting values. Creature and NPC records also have an inventoryBaseId that can be used on top of the baseId to base their inventories on another existing record.
The client's RecordHelper class has been heavily expanded to allow for the above mentioned functionality.
When players create spells, potions and enchantments as part of regular gameplay, they send RecordDynamic packets that provide the server with the complete details of the records that should be created. When they create enchantments, they also provide the server with armor, book, clothing and weapon records corresponding to the items they've enchanted.
This functionality added by this packet was originally supposed to be exclusive to the rewrite, but I've gone ahead and tried to provide it for the pre-rewrite in a way that can mostly be reused for the rewrite.
Prevents compiler warnings such as this:
```
/Users/Will/CLionProjects/OpenMW/apps/openmw/mwgui/windowbase.hpp:65:22: warning: 'onOpen' overrides a member function but is not marked 'override' [-Winconsistent-missing-override]
virtual void onOpen();
^
/Users/Will/CLionProjects/OpenMW/apps/openmw/mwgui/windowbase.hpp:38:22: note: overridden virtual function is here
virtual void onOpen() {}
^
```
added a MWWorld::ContainerStore to hold item copies which are then used to find
real items with findReplacement().
(storing the RefId could be a better solution but would probably leave tooltips broken...)
