* 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

* It's highly recommended to share one stateless handler with all the server-side channels.

* comment for prepareSharableHandlers

* Simplify comment

* remove comment

* supply test case

[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 #1241]optimize the codes for issue that Suggestion about the third part dependency of the RocketMQ client. (#1264)

[ISSUE #1156]Add new mqadmin API for ACL configuration

* [issue#1164]return the codes to original reput method part.

* [issue#1164]fix issue that Consumer Instance can't consume message from slave when cluster is in the high level tps and master has been killed.

* [issue#1164]if the broker is a master node,then modify reputFromOffset correctly.

* [issue#1164]add some coding comments.

* [ISSUE#1156]new mqadmin API for ACL configuration.Add dataVersion and write data to acl yaml config file in the acl module.

* [ISSUE#1156]add unit test cases for new acl mqadmin API command which adding dataversion part.

* [ISSUE#1156]implement update,delete and query Acl config version in new acl mqadmin API command.

* [ISSUE#1156]polish and optimize the implementation for new acl mqadmin API command.

* [ISSUE#1156]fix the issues that topicPerms and groupPerms can't be updated and there is NPE when querying acl config version.

* [ISSUE#1156]fix small issue that specify wrong plainAccessConfig attribute,the correct one is AccessKey.

* [ISSUE#1156]add updateGlobalWhiteAddr subcommand codes for mqadmin acl command.

* [ISSUE#1156]adjust some codes for cluster acl config version list in the mqadmin acl commands.

* [ISSUE#1156]add acl mqadmin command part in the acl user_guide docs.

* [ISSUE#1156]polish and optimize some part of acl mqadmin command codes.

* [ISSUE#1156]fix code comments issue that the first letter needs to be capitalized and adjust the contents of acl user_guide.

modify "TimeDelayLevel in not supported for batching"

config name wrong

[RIP-9] Commit docs Example_OpenMessaging.md 

Repair travis CI execute failed issue

(1) Polish message trace target channel (2) Fix the issue that consume message with namespace trace cannot found