KIJIMR-277. Cleanup leaked KijiTable instance in test

issue: https://jira.kiji.org/browse/KIJIMR-277
review: https://review.kiji.org/r/1836
Update versions for release
[maven-release-plugin] prepare release kiji-mapreduce-root-1.2.7
[maven-release-plugin] prepare for next development iteration
KIJIMR-272. Update REVIEWERS file.

issue: https://jira.kiji.org/browse/KIJIMR-272
review: https://review.kiji.org/r/1817
KIJIMR-276. Add a hadoop2, hbase96 bridge.

issue: https://jira.kiji.org/browse/KIJIMR-276
review: https://review.kiji.org/r/1839
KIJIMR-278. bump schema version; fix javadoc links; remove logOr* in tests

issue: https://jira.kiji.org/browse/KIJIMR-278
review: https://review.kiji.org/r/1861
EXP-416. KijiExpress doesn't log to job_history table

issue: https://jira.kiji.org/browse/EXP-416
review: https://review.kiji.org/r/1870
KIJIMR-280. Bumps version of CDH5 to bug fix version 5.0.1.

Testing done: mvn clean verify.

issue: https://jira.kiji.org/browse/KIJIMR-280
review: https://review.kiji.org/r/1876
KIJIMR-282. Add constants to JobHistoryKijiTable for job success and failure messages

issue: https://jira.kiji.org/browse/KIJIMR-282
review: https://review.kiji.org/r/1892
Update versions for release
[maven-release-plugin] prepare release kiji-mapreduce-root-1.2.8
[maven-release-plugin] prepare for next development iteration
SCHEMA-775. Refactor KijiColumnNameTranslator/HBaseColumnName/LayoutCapsule

issue: https://jira.kiji.org/browse/SCHEMA-775
review: https://review.kiji.org/r/1932
over-the-shoulder-reviewers: ['ajprax']