NPE when sending null transcoder

Not blocking anyone, but the library could be more resilient by properly handling a null transcoder instead of throwing the following exception:

Aug 27 09:40:07: INFO: Reconnecting due to exception on

{QA sa=localhost/127.0.0.1:11210, #Rops=1, #Wops=0, #iq=0, topRop=Cmd: -108 Opaque: 41 Key: 10 Exp: 10, topWop=null, toWrite=0, interested=1}

Aug 27 09:40:07: java.lang.NullPointerException
Aug 27 09:40:07: at com.couchbase.client.CouchbaseClient$9.gotData(CouchbaseClient.java:953)
Aug 27 09:40:07: at net.spy.memcached.protocol.binary.GetlOperationImpl.decodePayload(GetlOperationImpl.java:59)
Aug 27 09:40:07: at net.spy.memcached.protocol.binary.OperationImpl.finishedPayload(OperationImpl.java:178)
Aug 27 09:40:07: at net.spy.memcached.protocol.binary.OperationImpl.readFromBuffer(OperationImpl.java:162)
Aug 27 09:40:07: at net.spy.memcached.protocol.binary.GetlOperationImpl.readFromBuffer(GetlOperationImpl.java:31)
Aug 27 09:40:07: at net.spy.memcached.MemcachedConnection.handleReads(MemcachedConnection.java:563)
Aug 27 09:40:07: at net.spy.memcached.MemcachedConnection.handleIO(MemcachedConnection.java:480)
Aug 27 09:40:07: at net.spy.memcached.MemcachedConnection.handleIO(MemcachedConnection.java:261)
Aug 27 09:40:07: at com.couchbase.client.CouchbaseConnection.run(CouchbaseConnection.java:288)