Write tests to ensure that operations using DBDirectClient handle shard versioning properly

Since 2f7b99c780cfdce94b2888ddc8e078536af459a6 we disable all shard version checking while in DBDirectClient. We need to make sure that all operations that use DBDirectClient while operating on sharded collections (maybe just map-reduce?) properly do their own shard versioning handling and weren't relying on shard version checking to happen via DBDirectClient.

As for what the test could look like, I was thinking of something along the line of doing a map-reduce on a stale mongos right after a chunk migration and purposefully creating some orphaned data on the former chunk owner and making sure the map reduce sees the proper data