SPARK-1629. Addendum: Depend on commons lang3 (already used by tachyon) as...

SPARK-1629. Addendum: Depend on commons lang3 (already used by tachyon) as it's used in ReplSuite, and return to use lang3 utility in Utils.scala

For consideration. This was proposed in related discussion: https://github.com/apache/spark/pull/569

Author: Sean Owen <sowen@cloudera.com>

Closes #635 from srowen/SPARK-1629.2 and squashes the following commits:

a442b98 [Sean Owen] Depend on commons lang3 (already used by tachyon) as it's used in ReplSuite, and return to use lang3 utility in Utils.scala