added deleteProperty to FbWindow

src/FbTk/FbWindow.cc

@@ -389,6 +389,10 @@ void FbWindow::changeProperty(Atom property, Atom type,
                     data, nelements);
 }
 
+void FbWindow::deleteProperty(Atom property) {
+    XDeleteProperty(display(), m_window, property);
+}
+
 int FbWindow::screenNumber() const {
     return m_screen_num;
 }

src/FbTk/FbWindow.hh

@@ -137,6 +137,8 @@ public:
                         unsigned char *data,
                         int nelements);
 
+    void deleteProperty(Atom property);
+
     void setBufferPixmap(Pixmap pm);
 
     std::string textProperty(Atom property) const;