Fix dispose unwinding in KafkaTcpSocket
Fix dispose unwinding in KafkaTcpSocket

The dispose will now wait for the threads to unwind before disposing the
token

Jroland/kafka-net,bridgewell/kafka-net,nightkid1027/kafka-net,EranOfer/KafkaNetClient,PKRoma/kafka-net,martijnhoekstra/kafka-net,CenturyLinkCloud/kafka-net,aNutForAJarOfTuna/kafka-net,geffzhang/kafka-net,gigya/KafkaNetClient,BDeus/KafkaNetClient