Python API for org.apache.spark.mllib.feature.ElementwiseProduct

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #6346 from MechCoder/spark-7605 and squashes the following commits:

79d1ef5 [MechCoder] Consistent and support list / array types
5f81d81 [MechCoder] [SPARK-7605] [MLlib] Python API for ElementwiseProduct