Allow regularly-scheduled SMTP thumbnail / screenshot exporting, as well as other relevant information

Screenshots are already being captured and imported into the Control interface. We should be able to schedule regular delivery of these screenshots by machine or by machine group to ourselves or to clients who want to monitor their staff.

If this was in the form of a task-scheduling extension, it could also send other non-static information that managers might want to see, such as the idle time of each machine and the logged on user, but the easily automated export of the expanded thumbnail image would be a significant upgrade to this product.

Other options within the extension could include "Only export screenshot when user is logged in," and "Only update screenshot when idle time < screenshot interval"