Don't throw NPE when requesting a null value from Java API CassandraRow.
Allow null column values when JavaBeanColumnMapper is used.
Don't throw NPE when requesting a null value from Java API CassandraRow.
Allow null column values when JavaBeanColumnMapper is used.
Merge pull request #438 from datastax/wip-429

Don't throw NPE when requesting a null value from Java API CassandraRow.