Use an optimistic file watcher service which naively assumes files have
never changed while running Javascript tests rather than the default
Java 7 file watcher service -- this will slightly improve performance
on all platforms, and considerably improve performance on Windows due
to the outstanding WatchKey.close() bug, plus should work around a
threading bug in our model code that we have still yet to fix.
Merge pull request #397 from BladeRunnerJS/disable-file-watcher-service-while-running-js-tests

JSTD uses optimistic file watcher service which naïvely assumes files have never changed