* Polish 'no route info of this topic' exception.

* Write exception to log

* Modify logic that cannot connect to nameserver

* Solve the problem that the regression test does not pass.

* Adapt to lite pull consumer

* Make checkNameServerSetting function private and change its name.

* Remove the useless files

* Replace PermSize with MetaspaceSize, details see http://openjdk.java.net/jeps/122

* Update DLedgerCommitLog.java (#1145)

Delete useless code

* Remove the duplicate content

* Polish the comment (#1107)

* Minor Typo fix  (#860)

* [ISSUE #1082] Fix disconnection of HA (#1083)

* fixed the text description in chinese doc (#1339)

* fix /dev/shm not found on some OSs (#1345)

* Refactor the protection logic when pulling

* change the MQVersion variable to rocketmq 4.5.2 version;

* Minor polish

* Fix the wrong package name

* [maven-release-plugin] prepare release rocketmq-all-4.5.2

* [maven-release-plugin] prepare for next development iteration

* [RIP-15]Add Ipv6 support for RocketMQ

[ISSUE #598] Enhance transaction by putting messages that exceed max check times to system topic (#633)

* add logic of putting message that exceeds max-check-times to system topic TRANS_CHECK_MAXTIME_TOPIC

* add test case:testResolveDiscardMsg

* add @after logic to test case

* comment brokerController.shutdown and use mock

* add logic of resuming half message check

* add test case:resumeCheckHalfMessage

* delete commented codes

[ISSUE#662]capitalizing the first letter in comments and removing the unless comments for acl and msg trace feature codes. (#669)

* [ISSUE#662]capitalizing the first letter in comments and removing the  unless comments for acl and msg trace feature codes.

* [ISSUE#662]polish the acl feature codes.

* prepare to separate production-ready projects from the external projects

* Update fastjson to the latest stable version

* Clean code, don't list the default config in JVM

* Update README.md

* update the year info in NOTICE

* Release semaphore when timeout

* [ISSUE#525]add aclClient PRCHook for message track

* [ISSUE#525]add the apache license text,remove the merged from master branch

* [ISSUE#525]add aclClient PRCHook for message track,remove the merged content of notice and readme.md from master branch,add some unit test to increase the code coverage.

change fastjson to latest version