Progress so far on ticket #1468.

Work so far on http://eden.sahanafoundation.org/ticket/1468

We originally tried to incorporate using jQueryUI's progress bar to report the status of scheduled tasks to the UI, but weren't able to figure out how to send data from the controllers to the views without the use of some websocket-type library like comet. So we took a step back and added a argument to the schedule_task function for a user to be able to report the status of his/her scheduled task. Currently, after the task is inserted into the database, every second for 10 seconds the status of the task (one of RUNNING, COMPLETED, FAILED, or TIMEOUT) is written to a log file named according to that task.

We've also added a "reporting_percentages" dummy task to the tasks.py that shows how to report progress of tasks using the web2py scheduler. The percentages get reported in the "run_output" column of the "scheduler_run" table.

We added a test button to the Deployment (setup module) view to trigger the task from the UI.