This prevents the FlushThread from running while the interpreter is
shutting down and the import machinery is uninitialized.
Also fixed an issue where a KeyboardInterrupt while running multiple
suites with --continueOnFailure would skip to the next suite, rather
than exiting resmoke.py.
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.
