We don't need our own gettimeofday

Change-Id: Idc14d52bd685d338a86b3c904fdc3af739a568aa
Reviewed-on: http://review.couchbase.org/25544
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>