* flink任务支持

* flink任务支持

* Update zh_CN.js

* Update FlinkArgsUtils.java

* Update .escheduler_env.sh

Solve the problem that the user queue setting does not take effect

* service start exception modify

* master，worker start modify

* .env update

fix exception when failover worker if task host is null
fix process instance is null when task instance id == 0

Tgt invalid #742 fix，Concurrent task log bug #730 fix，logback.xml set log path support #723 fix (#761)

* mission log disorder，bug #751 fix

* the log path of the task and the log path of the task instance are different. The log cannot be viewed. #723

* the log path of the task and the log path of the task instance are different. The log cannot be viewed. #723 bug fix

* after starting kerberos authentication, tgt expires after one day，bug #742 fix

* log pattern modify

* LoggerServer remove comment code and ShellCommandExecutor modify

* PythonCommandExecutor modify

* Concurrent task log bug #730 fix

* remove invalid commit

* refactor to use SiftingAppender to write Tasks' log

* refactor to use shared CONSTS for TaskLogInfo

* fix refactor bug

* change log level to debug

* add unit test

* update escheduler-dao unit test

* update escheduler-api unit test

* update escheduler-api unit test

* add druid connection provider in order to change quartz default connection pool

* remove c3p0 in escheduler-api and escheduler-dao

* change method name queryByIdAndIp to queryBySessionId and queryByUserIdAndIp to queryByUserId

* change connectionProvider.class from c3p0 to druid

* change connectionProvider.class from c3p0 to druid

* bug fix #688，a user generated multiple ip session, the query error (#689)

* Dockerfile update

* worker code optimization

* filtering the log of one task to the log of another task

* update english documents

* refactor zk client

* update documents

* update zkclient

* update zkclient

* update documents

* add architecture-design

* change i18n

* update i18n

* update english documents

* refactor zk client

* update documents

* update zkclient

* refactor zkMasterClient/zkWorkerClient

* fix bug: close zk links .

* fix bug: close zk links .

* delete unused code

* update zkclient

* refactor zk client.

* update readme

* update readme

* update readme