MB-20397 - added TestMultipleMMapsOnSameFile
MB-20397 - added TestMultipleMMapsOnSameFile

Change-Id: I6d3cd18dcc418f07e51c26f9bbf53ee51b4f27a1
Reviewed-on: http://review.couchbase.org/66474
Reviewed-by: Marty Schoch <ba9951d7d66412e2a57aea395f01176a793cf5eb@gmail.com>
Tested-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>

steveyen/moss,steveyen/moss,couchbaselabs/moss