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.
