This version improves the disk backup and restore functions of DriveSort, which were not only slow, but uninformative and froze DriveSort while DriveSort they
were running. My motivation for this was that one of my 80GB disks nicely told me of its imminent failure via SMART, so I felt like doing a backup *quickly*.
With this version I added a mini background task scheduler, allowing to suspend, resume or abort the tasks independently or all at once. It also shows some
information about what they're up to. I improved the backup and restore speed by grouping the read and writes a bit.
I plan to use background tasks for other time consuming operations, such as the sort itself and the recursive save.