Fixes unreleased resource in TestShelfLife.

Reviewed by: milo
SCORE-75. Reimplements FreshKijiTableReader with improved concurrency

issue: https://jira.kiji.org/browse/SCORE-75
progression on InternalFreshKijiTableReaderRefactor.
completed implementation of Refactor.
Some aspects could use another pass.
not tested.
Implements RereadTask in Refactor.