SERVER-12949 Restore intermediate in-memory reduces, which are used to
keep the memory occupied by map/reduce small and spill extra large results
to disk.

Also adds a JS unit test to ensure this behaviour doesn't change
accidentally.
SERVER-13068 remove other occurance of replset last message
SERVER-12977 disallow empty write batches

Also fix shell batch processing to avoid extra empty batches.
Remove nYields from explain output in repair.js
SERVER-13207 Unordered batch writes to a shard with version mismatch can trigger dassert at mongos
SERVER-13208: dropDups should be ignored for index comparison
Blacklist storageDetailsCommand from sharding passthrough

It isn't intended to be run against mongos.