SERVER-15683: add optional filter to currentOpCtx command
SERVER-14412: make multi-update use collection intent locks
in shell, db.adminCommand should take 2nd optional param like runCommand
SERVER-15652: for parallel collection scan, make sure we call saveState on all iterators
SERVER-15729 make index rebuilder error message more clear
SERVER-15633 ShardingState::doRefreshMetadata should take a more granular lock than exclusive db
SERVER-14674 Shard dies during chunk migration if running repairDatabase and Compact
SERVER-15707 Fix leaks in C++ unit test framework
SERVER-15708 Don't leak stop words
SERVER-14668: Use SimpleMutex instead of SpinLock for LockManager

There can be contention on these, so spin locks are not appropriate.
SERVER-15777 findAndModify shouldn't explicitly create WriteUnitOfWork
SERVER-15797 doTTLForIndex shouldn't explicitly create WriteUnitOfWork
SERVER-15707 Fix C++11'ism and a long line
SERVER-15541 Don't do anything with MMAPV1Flush unless IsForMMAPV1
SERVER-13951 Changes that depend on rollback
SERVER-13635 Allow KVEngines to opt out of doc-locking
SERVER-1153 Clean up Heap1RecoveryUnit and implement recordChange()
SERVER-1153 Improve RecordStoreHeap

* Now supports rollback
* No more reinterpret_cast<>
* Fixed an iterator invalidation bug in the reverse iterator
SERVER-13635 Have KVCatalog do locking if the storageEngine doesn't support doc locking
SERVER-1153 Heap1 is now using KVEngine