Remove project-specific ntohll (use from libplatform)

Change-Id: I74cc3ffe4c57a4c963cdeb57e3e8810c01fdb8d0
Reviewed-on: http://review.couchbase.org/28858
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>