Move loggers to _private package. Change some i18n settings.
Split exceptions into separate interface. Removed unneeded methods and renumbered.
Make the JDBC repository less verbose for logging.
Merge pull request #6 from jamezp/logging-update

Logging Update
add to jberet-se/Batchlet1Test and JobDataTest to include transition elements (stop, fail, end).
add test to cold-restart a previously failed job execution, and related changes to JobOperatorImpl and sql to make it work.
add test for cold-starting from start position set by previous failed step.
add restartPosition to ddl and sql statements, and save restartPosition from JobExecution for restart.
add test to verify that a step's start count is calculated correctly during a cold-restart, and the step's start-limit is enforced in restart.