Update benchmark.asciidoc
Searcher might not be closed if store hande can't be obtained

Today we first get a reference to the IndexSearcher in #acquireSearcher
and then futher down we try to run Store#incRef() which might throw an
exception if the store is already closed. There is a small window
that allows this to happen during InternalEngine#close() when we try
to acquire the searcher at the same time and the engine is the last
resource that holds a reference to the store.

This commit only affects unreleased code since the Store's ref counting
has not yet been released.
Use loopback when localhost is not resolved
we use the "local host" address in sevearl places in our networking layer, if local host is not resolved for some reason, still continue and operate but using the loopback interface
[TEST] make fetch time in millis test more resilient
 beef up the fetch work, and increase teh number of iterations (since we count in nanos, but reports in rounded millis)
Don't lookup version for auto generated id and create
When a create document is executed, and its an auto generated id (based on UUID), we know that the document will not exists in the index, so there is no need to try and lookup the version from the index.
For many cases, like logging, where ids are auto generated, this can improve the indexing performance, specifically for lightweight documents where analysis is not a big part of the execution.
we need to make sure that we don't do the optimization on recovery
disabling auto generated id should happen on the state the primary operation happened on
we check, before we operate on the replica, if the state has changed, and we need to apply the replica operations to the new state. But, we should make sure we disable the auto generate id on the state the primary operation happened on, since the replica might have gone through recovery, move to started, and then the shard routing will be started in the new state we sample in the replica operation
generic potential dup flag on replication request
create a generic potential dup flag, that can be used to optimize the auto generate id
better handling potential dup flag, also on index