Previously, unstacking items for a player led to a PlayerInventory packet being sent about the items' removal.
This change makes it so both a packet about their re-addition and their removal are sent instead, cancelling each other out, which is inelegant, but arguably preferable to complicating the sending of PlayerInventory packets again.
Whenever an item is added to or removed from the player's ContainerStore, that player sends a PlayerInventory packet with just that addition or removal.
This eliminates all the unnecessary packet spam related to oversized PlayerInventory packets that had existed in one form or another since the initial implementation of inventory sync in 1b259e2d33
Additionally, move booleans from BasePlayer to LocalPlayer when they are only needed on the client, and make the usage of the isReceivingQuickKeys boolean consistent with the new isReceivingInventory boolean by having them both in the processors of their associated packets.
A Warning indicates a potential problem in the content file(s) that the user told OpenMW to load. E.g. this might cause an object to not display at all or as intended, however the rest of the game will run fine.
An Error, however, is more likely to be a bug with the engine itself - it means that basic assumptions have been violated and the engine might not run correctly anymore.
The above mostly applies to errors/warnings during game-play; startup issues are handled differently: when a file is completely invalid/corrupted to the point that the engine can not start, that might cause messages that are worded as Error due to the severity of the issue but are not necessarily the engine's fault.
Hopefully, being a little more consistent here will alleviate confusion among users as to when a log message should be reported and to whom.
conversion from 'const float' to 'int', possible loss of data
conversion from 'double' to 'int', possible loss of data
conversion from 'float' to 'int', possible loss of data
