回退分组的代码修复bug
Merge branch 'master' of https://github.com/opencloudb/Mycat-Server

Conflicts:
	src/main/java/org/opencloudb/mpp/DataMergeService.java
	src/main/java/org/opencloudb/mpp/MutiDataMergeService.java
Merge branch 'master' of https://github.com/opencloudb/Mycat-Server

Conflicts:
	src/main/java/org/opencloudb/mpp/DataMergeService.java
Merge branch 'master' of https://github.com/opencloudb/Mycat-Server

Conflicts:
	src/main/java/org/opencloudb/mpp/DataMergeService.java
resolve conflict

Conflicts:
	src/main/java/org/opencloudb/mpp/DataMergeService.java
Merge branch 'master' of https://github.com/opencloudb/Mycat-Server
解决测试程序问题
解决测试程序问题
Merge branch 'master' of https://github.com/jaggerliu/Mycat-Server.git
Merge remote-tracking branch 'mycat/master'
Merge branch 'master' of https://github.com/opencloudb/Mycat-Server

Conflicts:
	src/main/java/org/opencloudb/mpp/DataMergeService.java
Merge branch 'master' of https://github.com/opencloudb/Mycat-Server

Conflicts:
	src/main/java/org/opencloudb/mpp/DataMergeService.java
在配置文件中增加sharding-murmur-hash
Merge branch 'master' of https://github.com/runfriends/Mycat-Server
Merge remote-tracking branch 'mycat/master'
若异常是IO异常，即连接关闭，就不打印堆栈日志
修复当连接不上的时候Handler为空导致的空指针异常
解决空指针问题：表不存在时一个select多表查询的语句出现空指针
Merge pull request #25 from jaggerliu/master

解决测试程序问题
Merge pull request #31 from wdw1206/master

解决druid解析空指针问题：表不存在时一个select多表查询的语句出现空指针
Merge remote-tracking branch 'origin/master'