SCHEMA-541. Kiji.openTable() fails to report non existing tables under system-2.0

- KijiTableNotFoundException now takes a KijiURI instead of a naked table name.
- Implement toString() in HBaseKijiMetaTable, HBaseTableLayoutDatabase.
- Rewrite TestHBaseMetaTable without mocks.
- Update HColumnDescriptor to use new builder pattern (fix deprecation warning).

issue: https://jira.kiji.org/browse/SCHEMA-541
review: https://review.kiji.org/r/1033