Merge more of SMA Resource Monitor's features into File Arrival

File Arrival has been a nice addition to OpCon, but there are still times when SMA Resource Monitor (SMARM) is more effective. The items below need to be added to File Arrival to more fully replace SMARM.

* There should be a setting to keep the Job open responding to each file which arrives during the specified time.

** A minimum file count should be set. The Job should fail if it detected less than this number of files during the specified time window.
** An optional maximum file count should be added. This Job will close if this maximum count is reached before the defined end time.
** The defined event should be sent as the Job detects new files.
** The Job should keep track of which files it already detected. This will avoid the need to move files out of the monitored directory.

* Add a setting to trigger the File Arrival off of:

** Created time
** Modified time
** Accessed time

* The Job should have a maintenance mode of some sort. Agent upgrades are currently complicated by t