implements a property handler for use with an ::com::sun::star::inspection::ObjectInspector
which provides properties for button controls which support submission of XML forms.
The handler expects a value named "ContextDocument" in the context in which it is created.
That is, the ::com::sun::star::uno::XComponentContext used for creating the
CellBindingPropertyHandler is examined for a value with this name. If the object in this
value denotes a XML form document (indicated by supporting the ::com::sun::star::xforms::XFormsSupplier
interface), this document is used to examine the XML submissions which the button can be bound to.
