Set defaults directly rather than calling the setters in lcb_create

Change-Id: I27f195cf6e0667d14f01b24c3c49d54b12c85136
Reviewed-on: http://review.couchbase.org/27880
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>