Reverts to emulating the write concern to work around how prior to
MongoDB 3.4, operations that did writes didn't necessarily accept a
writeConcern object.
Also limits the usage of replica set connection strings to only the
write_concern_majority_passthrough.yml test suite to work around the
lack of complete support of MongoURI parsing in versions of the mongo
shell prior to MongoDB 3.4.
(cherry picked from commit 264d971842)
Split out the passthrough tests into separate suites. The MongoDB
deployment is started up by resmoke.py so that we can record the
success/failure of each individual test in MCI.
Added support for parallel execution of tests by dispatching to
multiple MongoDB deployments.
Added support for grouping different kinds of tests (e.g. C++ unit
tests, dbtests, and jstests) so that they can be run together. This
allows for customizability in specifying what tests to execute when
changes are made to a particular part of the code.
