Move getopt header to make it easy accessible

Change-Id: Icea6b3a354b41e727a4e756737b34f88bf61c961
Reviewed-on: http://review.couchbase.org/32415
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>