Please review this pull request.

Author: Jihong MA <linlin200605@gmail.com>

Closes #5933 from JihongMA/SPARK-7265 and squashes the following commits:

dfaa971 [Jihong MA] SPARK-7265 minor fix of the content
ace454d [Jihong MA] SPARK-7265 take out PySpark on YARN limitation
9ea0832 [Jihong MA] Merge remote-tracking branch 'upstream/master'
d5bf3f5 [Jihong MA] Merge remote-tracking branch 'upstream/master'
7b842e6 [Jihong MA] Merge remote-tracking branch 'upstream/master'
9c84695 [Jihong MA] SPARK-7265 address review comment
a399aa6 [Jihong MA] SPARK-7265 Improving documentation for Spark SQL Hive support