SERVER-15262: fsynclock thread after downgrade to global S should unlock flush lock as it doesn't need it
SERVER-13635: fix list race in kv database catalog
SERVER-13635: make some test storage engine agnostic
SERVER-15541 RecoveryUnit::commitAndRestart to avoid WriteUnitOfWork
SERVER-15541 SERVER-15652 implement timing-based yielding
SERVER-15713: do not buffer replicated ops once primary
SERVER-15060: remove failing large set test
Merge remote-tracking branch 'root/master'
SERVER-15733 Wait longer for a primary in jstests/replsets/replsetprio1.js.

With the 30 second lease time, it is possible for it to take just over 30 seconds to elect
a new primary in replsetprio1.js.  Bump the wait time in the test to 60 seconds.
new recovery unit method
SERVER-15541 add invariants to catch yielding within a WriteUnitOfWork
SERVER-15262 Yield the flush lock even if it is for the LocalDB
SERVER-15686 remove unneeded blacklist code and tests from RangeDeleter
Merge remote-tracking branch 'root/master'
SERVER-13635: make repl test oplog storage agnostic
SERVER-15750 Break deadlock cycle by not holding the global lock while acquiring the bgsync mutex.
SERVER-15747 stepdown for the lease time after failed election
SERVER-15711: DurThread is at front of queue, but times out
SERVER-15706 Refactor internal user authentication
SERVER-15761 Acquire collection-level lock for getting TTL indexes.

Also need to check that the CollectionCatalogEntry is non-NULL
since the specified namespace may not be found in the catalog.