Add Pool.removeHandleOfElementFromBeingUsed
Add AllocationStrategy.allowStealing
Add allowStealing method to all AllocationStrategy implementations
Refactor Pool.getElement
Make PoolTest.ResizeBy static
Add PoolTest.SingleElementCanBeStolen
Add PoolTest.poolStealsElementWhenStrategyForbidsCreatingNewOneButAllowsStealing
Pass PoolTest.poolStealsElementWhenStrategyForbidsCreatingNewOneButAllowsStealing
Add passing PoolTest.poolDoesNotStealElementWhenStrategyForbidsBothItAndCreatingNewOne
Change PoolTest.SingleElement{CanBeStolen -> WithSettableStealingPolicy}
Add passing PoolTest.poolStealsWhenStrategyMutatesToAllowIt
Add passing PoolTest.poolStopsStealingWhenStrategyMutatesToForbidIt