Allow build from source bundle

Change-Id: I952b3a5e78e11b744c15b16b652ec64aac17f390
Reviewed-on: http://review.couchbase.org/36218
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>