Draw2D touch version 5.0.4 released

+ don't propagate the keydown/keyup event to the canvas if the target was an textarea or input field
+ new example "policy_drag_copy" to show how to copy a shape during a drag&drop operation
+ restore "ports" from the JSON file into a node. It is now possible to create ports for a shape with JSON
+ new method draw2d.shape.node.Node#setPersistPorts to handle port serialization
+ fixing the PERT demo example
+ adding padding to the "sparkline" diagram.
+ new example how to use the port read/write: "port_serialize". Reading port configuration from JSON.
+ don't propagate onKeyUp/onKeyDown to the canvas if the target was an textarea ("input" was already checked)