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
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
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'
子查询的别名条件忽略掉,不参数路由计算，否则后面找不到表,测试语句SELECT  UM.UserId , UM.MenuId ,SM.ParentId ,SM.FullName , SM.Description , SM.Img , SM.NavigateUrl ,SM.FormName ,SM.Target ,SM.IsUnfold FROM    Lever_SysMenu SM INNER JOIN ( SELECT UR.UserId AS UserId ,  RM.MenuId AS MenuId FROM   Lever_RoleMenu RM  INNER JOIN Lever_UserRole UR ON RM.RoleId = UR.RoleId  UNION SELECT UserId ,   MenuId FROM   Lever_UserMenu   UNION SELECT U.UserId ,      RM.MenuId   FROM   Lever_User U     LEFT JOIN Lever_RoleMenu RM ON U.RoleId = RM.RoleId    WHERE  U.UserId = '8d28533f-1762-4e79-b71f-64eb1a50cb8b' ) UM ON SM.MenuId = UM.MenuId   WHERE   UM.UserId = '8d28533f-1762-4e79-b71f-64eb1a50cb8b'  AND SM.Enabled = 1  ORDER BY SM.SortCode
有些sql没有别名时出现空指针
Merge pull request #33 from opencloudb/master

修复当连接不上的时候Handler为空导致的空指针异常
Merge pull request #32 from wdw1206/master

子查询的别名条件忽略掉,不参数路由计算，否则后面找不到表,测试语句SELECT  UM.UserId , UM.MenuId ,SM.Paren...
add catlet dir