Autostart fully implemented, but still a little messy. Added color coding for status labels. Job status boxes in left frame are now sorted by status (rendering->paused->waiting->stopped->finished) then chronologically oldest-first within each category. Highest ranked job (if there is one) is now selected at GUI startup.  Added new job status 'Paused' for renders that were stopped by the autostart function and will resume once the high priority render is finished. It's otherwise identical to 'Stopped'. Still need to update safety checks that need to account for the new status. Also added a method to Job for starting renders from autostart that accounts for the different possible statuses.