Made various changes and fixes to the task system:
- Tasks are built around QtConcurrent rather than QThread. Reduces
code complexity significantly.
- Task error reporting is now streamlined in both TaskManager and
TaskDialog.
- Moved ProjectImport/Save/LoadManager to the app/task folder
An earlier commit addressed faulty TaskViewItem ordering by changing
insertWidget to addWidget. Turns out this was the wrong strategy since the
insert was used to get widgets above the stretch. The correct strategy is
using insert(count()-1) instead of insert(0)
itsmattkc