SCHEMA-695. Rebase and merge all Cassandra code onto master

issue: https://jira.kiji.org/browse/SCHEMA-695
review: https://review.kiji.org/r/1963
SCHEMA-842.  Translate eid components names to C* col names.

Avoid conflicts with CQL keywords, other columns (e.g., "version") in
the Cassandra Kiji tables.

review: https://review.kiji.org/r/1970
issue: https://jira.kiji.org/SCHEMA-842
SCHEMA-840. Iterable based (instead of iterator based) KijiResult API

issue: https://jira.kiji.org/browse/SCHEMA-840
review: https://review.kiji.org/r/1965
SCHEMA-841. Implement KijiRowData ontop of KijiResult

issue: https://jira.kiji.org/browse/SCHEMA-841