Import wiredtiger-wiredtiger-2.4.0-275-gc4f14ea.tar.gz from wiredtiger branch develop
Tune WT default cache_size up to 50% memory
SERVER-16023: abort mongod on WT_PANIC
update-vendor-wiredtiger: exclude tools/third_party
Import wiredtiger-wiredtiger-2.4.0-285-g0d497d3.tar.gz from wiredtiger branch develop
fix compilation for WT Windows
SERVER-15541 MMAP v1 only takes LockMongoFilesShared for yielding plan executors
SERVER-16012 Rename heap1 to inMemoryExperiment
Don't check the time more than needed when locking
SERVER-16031 Call cleanShutdown rather than deleting KVEngines

Resolves some race conditions on shutdown.
SERVER-16026: on secnodaries w/doc locking, secondary unique indexes always have to be unchecked during batch
SERVER-16050: Do not sleep when yielding

Sleeping should not be necessary as ordering is purely determined
by the lock manager
SERVER-16048 Eliminate double copy and most ref-counting with RecordData
SERVER-16026 Improved combination of ns and _id field into hash value for worker thread selection.
Import wiredtiger-wiredtiger-2.4.0-293-g4e4bf47.tar.gz from wiredtiger branch develop
Don't log on first pass through lock wait loop
SERVER-16016 WiredTigerRecordStore::Iterator should not try to restore its state if it is EOF
SERVER-15645: clean up WiredTigerRecordStore::insertXXX
SERVER-15645: allow writes to oplog in IX by managing reads to block on oldest ts
SERVER-16046: only one thread should cleanup capped collections