CCBC-221: Don't use iops in minimal.c

The iops usage is an advanced feature and is not needed in a normal
application. Generally only users already using an event loop should be
using this example.

Change-Id: I6ab62e385b07744119a3150608992d505af54685
Reviewed-on: http://review.couchbase.org/27088
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
CCBC-183 Improve lcb_get_replica()

Now it is possible choose between three strategies:

1) LCB_REPLICA_FIRST: previously accessible and default now, when the
   caller will get first successful replica or error

2) LCB_REPLICA_ALL: Ask all replicas to send keys

3) LCB_REPLICA_SELECT: select particular replica by the index (from 1
   to 3 inclusive). This one is faster, but can generate false
   negatives

Change-Id: Ib50a578d6ac99a0e1cb05c6a6a82b7c0c13082a5