Minor cleanups and fixes in helma.util.CronJob:

* Send sub-properties of app properties that start with "cron." so we don't have to 
  do the filtering ourselves.
* Be tolerant of whitespace in cron job time specs (e.g. cron.foo.minutes = 0, 15, 30, 45)

src/helma/framework/core/Application.java

@@ -1588,7 +1588,7 @@ public final class Application implements Runnable {
      */
     private void executeCronJobs() {
         // loop-local cron job data
-        List jobs = CronJob.parse(props);
+        List jobs = CronJob.parse(props.getSubProperties("cron."));
         Date date = new Date();
 
         jobs.addAll(customCronJobs.values());