[SPARK-5704] [SQL] [PySpark] createDataFrame from RDD with columns

Deprecate inferSchema() and applySchema(), use createDataFrame() instead, which could take an optional `schema` to create an DataFrame from an RDD. The `schema` could be StructType or list of names of columns.

Author: Davies Liu <davies@databricks.com>

Closes #4498 from davies/create and squashes the following commits:

08469c1 [Davies Liu] remove Scala/Java API for now
c80a7a9 [Davies Liu] fix hive test
d1bd8f2 [Davies Liu] cleanup applySchema
9526e97 [Davies Liu] createDataFrame from RDD with columns