Comment 6 for bug 709022

Well I made a this drag-an-made-a-stack feature, but the popover ui with a slinghot-like grid/list view is missing. I cannot accomplish it because I really don't know how to show a Gtk.PopoverMenu or Gtk.Popover which is connected to the DockElement, and it replaces a standart Gtk.Menu. This feature is related to: the https://bugs.launchpad.net/plank/+bug/1279895

Current version allows:
- drag an dockitem and drop on another dockitem to create a new stack
- drag and dockitem anddrag on another stack to append (add it to) the created stack
- the stacks are created in the launchers/ folder which consists symlinks to .desktops, and files
- during the dragging action the hovered icon is lighter than in normal state (I think all siblings should be darken and hovered lighten).
- if the stack is located in launchers then there is a new option above the "Kepp in dock" called "Stack settings" (should be renamed for better l10n). There user can configure the name of the stack, show where is the dockstack located.

I need some extra days to make a way better user experience (animation) when user drags an icon on other icon to create a stack.

I haven't published it yet, since I needs to change some things before attempting to collect a bounty. The progress is covered in issues on https://github.com/piqus/pantheon-dock/issues