Revert 901008f..9e0b380

This rolls back to commit 901008f1965266b791b32450afd5466e0a44e540.
Details:
- com.wf.quartz.task.api bundle:
* Task and MultipleTask interfaces converted to abstract classes.
* ScheduledTask class added for schedule tasks in quartz.
* MANIFEST.MF updated to handle changes in bundle.
- com.wf.quartz.job.service bundle:
* UniforceJobHandler interface renamed to QuartzJob
* UniforceJobHandlerWrapper renamed to QuartzJobWrapper
* Other bundles files adapted the changes.
- com.wf.quartz.job.cron bundle:
* DummyTask and DummyMultipleTask added for testing.
* MANIFEST.MF file adapted the changes.
* CronJob class became a ScheduledTask
* Activator class adapted to changes.
- com.wf.quartz.job.simple bundle:
* Adapted the renaming and altering operations.