Implement queued database operations per user/subsystem

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Requirements:

• Database is implemented (Implement a database of some sort. #4)

Reason:
Since this game is web based, all requests will be async. We need to be able to ensure proper behavior, should a player open 10 tabs and click the buttons all at once. This demands that each response is blocked on a queue of database operations for that user, such that we do not get some weird bugs where they can buy things for free. It is per user for most operations, but things such as towns and stuff will need to be queued for that specific object.

[hakusaro]

on it doc

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Dont assign yourself a task when the requirement isnt complete. Project management 101.