Some warnings removed.
Fixed source url for async copyed files.

Implemented undo stack for moved unselected items.

Transparent drawing view is separated as DesktopView and doesn't manages strokes selections and movements.

Sankore 1224 z-layer reordering amended Delegate button progressbar added retrieving data from the internet

Fixed working on mac.

removed fix from Aleksei for big copying file because doesn't work with audio/video/flash element on mac