* 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