breakdancer unit tests very slow on Windows

When running on Windows the breakdancer tests are very slow - ~5x slower than Linux:

00:07:29.937  5/31 Test  #5: memcached-breakdancer-engine-tests_0 ...   Passed  177.34 sec

(source: http://factory.couchbase.com/job/memcached-gerrit-master/2313/label_exp=sherlocker-windows/console)

on Linux (Ubuntu 12.04):

00:06:01.010  5/30 Test  #4: memcached-breakdancer-engine-tests_0 ...   Passed   33.47 sec

This obviously slows down the overall commit-validation runtime (as we have to wait for the longest task to complete).

If I had to guess I'd say this is related to process spawning (via engine_testapp) of the individual tests - Windows has a reputation for being slow at this compared to Linux).