This will give storagenode operators a better idea of whether the memory
allocated to the usedserials store is sufficient.
Change-Id: I5c30f2e39473a573f43409511ad9e2e32680479c
Implement an in-memory store for keeping track of order limit serial
numbers. It automatically deletes items if its size exceeds a configured
limit.
This change is part 1 - it creates the store
In part 2, the in-memory store will replace the usedserials database
Change-Id: I36f540ed809f034a27c1d7cede8a0a8b080af818
