* added the progress dialogue to the set of widgets

* added the progress dialogue to the set of widgets
- the Cancel-button is currently disabled because the core doesn't respond correctly (might be my fault though)
- note that the File's Owner of the nib-file is of type VLCInteraction because the class can't resolve its outlets otherwise

* WIDGET_TEXT and WIDGET_INPUT_TEXT are still missing, but will come in the next couple of days

As usual, comments on the implementation and the GUI-design are welcome :)