This is the first time official release of RocketMQ-Spring-Boot as a sub-project of Apache TLP RocketMQ in the community. In this release, it includes several new features, improvements and fixed for the issues reported for rocketmq-external incubating.

New Feature:

1. Sending the message in transactional
2. Support send DelayTimeLevel message
3. Make RocketMQ native API transparent; only operate with Spring Message API rather than RocketMQ client API.

Improvement:

1. Add samples to demonstrate the usage of the RocketMQ-spring-boot/starter and cover all client scenarios.
2. Polish the code with Spring standard (lifecycle, BeanCreating conditional, Bean Initialize, AutoConfigure Test, etc)
3. Adjust the directory hierarchy and separated the functions with different level projects, i.e. spring-boot, spring-boot-starter and sample.
4. Refactor the packages and make code clearer with full qualified naming and standard java doc comments.

Bug:

1. Bean method 'rocketMQTemplate' not loaded
2. Inaccurate judgment for message type in defaultRocketMQListenerContainer
3. spring-boot-starter Document update
4. The annotation @RocketMQMessageListener(consumeThreadMax=4, topic = "${sep.queue.meta}" cannot take effect.