In order to enable support of authoritative collections we have to handle the case of having an authoritative CSS.

In order to do this the following protocol has to be followed:

• If the versions are comparable then we use that information to determine if the router is stale
• Otherwise, if the router is more recent than us, or if the versions can’t be compared:
  • We wait until the shard’s version matches the router’s
  • OR we wait until the shard has replicated up to the configTime received and it is majority available, whichever of these two events come first
  • Once we’re done waiting, we compare against the current state and if it’s a mismatch then the router is guaranteed to be stale

The comparison checks must also consider a critical section not being present as otherwise we'd be making comparisons mid-way through a change in the CSS.

Note that we must also handle the case of a CSS becoming non-authoritative by the time we finish the wait, in which case we should fallback to the handling done by non-authoritative CSS