Create Persistent Event Logs For Job Scheduler

Currently the job scheduler event log is restricted to Quartz generated events (job fired, job completed), is restricted to one machine, and is in memory. This makes review of job status and job errors problematic, particularly in a clustered environment. I propose that the event log be replaced with a persistent, DB-backed event log. This log would combine the Quartz-generated events and any logging the Job developer chooses to include in the event log. This will prevent the need to skim through catalina.out to find job execution errors or info statements and will allow an administrator to look at job execution event logs across a cluster.