Abort for missing hard requirements

Change-Id: I2b2c56d06ec906fa1f3ecb2b8036ba9294a350a1
Reviewed-on: http://review.couchbase.org/33433
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>