SPARK-2192 [BUILD] Examples Data Not in Binary Distribution

Simply, add data/ to distributions. This adds about 291KB (compressed) to the tarball, FYI.

Author: Sean Owen <sowen@cloudera.com>

Closes #3480 from srowen/SPARK-2192 and squashes the following commits:

47688f1 [Sean Owen] Add data/ to distributions
[SPARK-4664][Core] Throw an exception when spark.akka.frameSize > 2047

If `spark.akka.frameSize` > 2047, it will overflow and become negative. Should have some assertion in `maxFrameSizeBytes` to warn people.

Author: zsxwing <zsxwing@gmail.com>

Closes #3527 from zsxwing/SPARK-4664 and squashes the following commits:

0089c7a [zsxwing] Throw an exception when spark.akka.frameSize > 2047
[SPARK-4661][Core] Minor code and docs cleanup

Author: zsxwing <zsxwing@gmail.com>

Closes #3521 from zsxwing/SPARK-4661 and squashes the following commits:

03cbe3f [zsxwing] Minor code and docs cleanup