The drag'n'drop library, used internally by certain base panels to allow for drag'n'drop functionality, like spawnmenu's customizations.
Calls the receiver function of hovered panel.
Clears all the internal drag'n'drop variables.
Handles the drop action of drag'n'drop library.
Handles the hover think. Called from dragndrop.Think.
Returns whether the user is dragging something with the drag'n'drop system.
Starts the drag'n'drop.