Let project give out list of currently opened stacks
 Selector tool: duplicate pointer in other open stacks
Selector tool: add missing redraw() and handleKeyPress() methods
Selector tool: add screenshot of cursor mirroring to documentation
Selector tool: use different cross-hair for duplicated cursors
Merge pull request #486 from tomka/selector-mirror-mouse-crosshair

Selector tool: stack mirrored mouse crosshair