[SPARK-8348][SQL] Add in operator to DataFrame Column

I have added it for only Scala.

TODO: we should also support `in` operator in Python.

Author: Yu ISHIKAWA <yuu.ishikawa@gmail.com>

Closes #6824 from yu-iskw/SPARK-8348 and squashes the following commits:

e76d02f [Yu ISHIKAWA] Not use infix notation
6f744ac [Yu ISHIKAWA] Fit the test cases because these used the old test data set.
00077d3 [Yu ISHIKAWA] [SPARK-8348][SQL] Add in operator to DataFrame Column