mc-kvstore does not retry commands if mc_daemon crashes

I was creating 100k items on a fresh cluster and some of couch_db:update_docs calls in mccouch failed thus causing mc_daemon to crash and thus to close a connection. After all sets where done there were 100k items available in memcached. But only about 90k of them were persisted and available from couchdb. Thus it seems that ep-engine or mc-kvstore does not attempt to retry sending commands if the connection to mccouch is being closed.