add parser for FailedjobRetryCount
add JobFailRetrycommand and its related test case
add extra test case for FailedJobRetry
revert jobEntity back to what it was. Change not needed
enhance FailedJobRetry based on Tijs' comments
change logging in JobRetryCmd to sl4j
Merge branch 'failRetry' of https://github.com/smirzai/Activiti
Small changes to retry pull request