OI File Manager: apply patch by damienix: delete in thread.
Update issue 294
A new background thread is created for deleting files and folders.
It supports deleting multi-selected files.
A toast is shown at the beginning and at the end of the delete action.
* add a progress bar (currently only a Toast is shown)
Summary: OI File Manager: copy and move in thread showing progress bar
Labels: Type-Defect, Priority-Medium, Stack-FileManager
Similar to issue 294, but extend it to also support copy and move commands.