SERVER-16259 Rocks storage engine needs to support document locking

SERVER-16309 - Fix rocks_recovery_unit

SERVER-15744 Concurrency fix -- Fixed jstests/core/bench_test3.js

Signed-off-by: Matt Kangas <matt.kangas@mongodb.com>
SERVER-16279 change node B to arbiter in rollback_too_new
SERVER-16376 Make nodes in jstests/gle/get_last_error.js choose their sync source deterministically.

The test expects w:majority writes to happen faster than a heartbeat interval when a single
non-primary node fails.  If, however, that failed node is the intermediate in a replication
chain, there can be a multi-second lag until the other nodes recognize the failure.  Change
the test to disallow chaining, because it is not the subject of the test.
Merge remote-tracking branch 'upstream/master'