AITFIVE-203 kafka crawl log feed
fix log messages to say "kafka"
switch to org.apache.kafka.clients.producer.KafkaProducer to see if we can avoid the InterruptedException at the end of the crawl (and log warnings on failure to send message)
new style kafka configuration properties
so that it can appear in the crawl log, add contentSize to CrawlURI extraInfo, for http transactions (the only case in heritrix currently where contentLength and contentSize differ)
Merge branch 'extra-info-size' into aitfive-203
for kafka/amqp crawl log feeds, remove now redundant contentSize from extraInfo
Merge branch 'aitfive-203' of github.com:nlevitt/heritrix3 into aitfive-203
Revert "switch to org.apache.kafka.clients.producer.KafkaProducer to see if we can avoid the InterruptedException at the end of the crawl (and log warnings on failure to send message)"

This reverts commit d2f70e5c9767edeadabfbc7424a1eeddc712b2ae.

Conflicts:
	contrib/src/main/java/org/archive/modules/postprocessor/KafkaCrawlLogFeed.java
Revert "Revert "switch to org.apache.kafka.clients.producer.KafkaProducer to see if we can avoid the InterruptedException at the end of the crawl (and log warnings on failure to send message)""

This reverts commit a0f70d0865198908e2fa700772ca0694ee079a96.
make sure the kafka producer thread is not in the ToePool thread group, to stop it from being interrupted at the end of the crawl
Merge pull request #108 from nlevitt/aitfive-203

kafka crawl log feed