HIVE-5614 : Subquery support: allow subquery expressions in having clause (Harish Butani via Ashutosh Chauhan)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1544857 13f79535-47bb-0310-9956-ffa450edef68
HIVE-5763: ExprNodeGenericFuncDesc.toString() generating unbalanced parenthesises (reviewed by Ashutosh)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1544885 13f79535-47bb-0310-9956-ffa450edef68