v2.4.12.RELEASE

Change log:

cac1ced Upgrade grgit plugin
8163abd Upgrade versions; prepare for release
e777a6b Javadoc Polishing
e307771 Don't cache tx producers after reset()
2b02987 Adjust repositories in build.gradle
fa50a4a GH-1637: Fix TopicPartitionOffset.hashCode()
8e9f9de GH-1631: fix missing @sendto for cglib proxies
c52d736 GH-1519: Fix @sendto on @KafkaHandler
724ac8a GH-1621: More back-ported test fixes
21f511b GH-1621: Fix test for back-port
c240737 GH-1621: Fix nack() with Tx Batch Listener