returns the data for the pdk identifier idString from the widget
data base. Dynamically adds the "idstring", "parentidstring", and
"childidstrings" keys to the data found in the XML data base.
removes the widget node specified by the pdk id idString from the
widget data base. Also removes the wrapping node, if this is empty
after the operation (and if the wrapping node is not the root node...).
initialize the widget node specified by the ID string idString with
the data from the WidgetData instance wData.
If no node of the specified pdk ID exists, it is automatically created
as a child of the node specified by the "parentidstring" key in
wData.
factory function for creating the GUI subsystem of pdk. See the
_Gui constructor for the arguments of this function. If called more
than once, returns a reference to the singleton created in the first call.