[BUG] world:clear() does not invoke hooks

[vnnh]

Calling world:clear(id) does not invoke any OnRemove hooks for components that the entity might have.

local component = world:component()
world:set(component,jecs.OnAdd,function()
    print("added")
end)
world:set(component,jecs.OnRemove,function()
    print("removed")
end)

local entity = world:entity()
world:add(entity,component)
world:clear(entity)
-- only prints added
-- changing the :clear() to :delete() prints removed as expected

[Ukendio]

Fixed in #141