[SPARK-2050][SQL] LIKE, RLIKE and IN in HQL should not be case sensitive.

Author: Michael Armbrust <michael@databricks.com>

Closes #989 from marmbrus/caseSensitiveFuncitons and squashes the following commits:

681de54 [Michael Armbrust] LIKE, RLIKE and IN in HQL should not be case sensitive.

(cherry picked from commit 41db44c428a10f4453462d002d226798bb8fbdda)
Signed-off-by: Reynold Xin <rxin@apache.org>