Lua API for creating new objects

There are a bunch of considerations to keep in mind:

1. In multiplayer, creating an object is fundamentally an asynchronous operation. At minimum, the object's refId should be assigned by the server to ensure uniqueness.
2. Objects might have parameters other than record id, such as condition of weapons, or souls in soul gems. There needs to be a way to set those values at the same time as the object is created, to avoid multiplying cross-script delays.
3. In Morrowind (and OpenMW), objects can exist either in a cell, or in an inventory (an actor's or a container's). We should structure the API in such a way that the logic of object creation is separate from the place where it gets created, to avoid duplicating functionality.
4. Currently there is no final decision on how objects with attached scripts should behave when they move from a cell into an inventory. Identical objects stack, so there are multiple reasonable ways of handling identical objects with some of them having attached scripts.

A vague draft of how an API addressing all of these might look:

local core = require('openmw.core')
local types = require('openmw.types')

-- creates a temporary object, which doesn't exist in the world yet
-- the object won't be synchronized or even assigned a final refId
-- until it is actually added to the game world
local newObject = core.createObject('myWeaponId')
-- make the item broken, still no sync of any kind
types.Weapon.stats.dynamic.condition(newObject).current = 1
-- drop the object in a cell, actually gets synchronized to other scripts at this point
newObject:teleport('Balmora', util.vector3(1, 2, 3))