Create backdrop for text label
1 In createPin(event), added two statements
   objectLabel.children['rect'].visible = true;
   objectLabel.children['rect'].visible = fasle;

2. In functoin zxcMakeTextBox, event zxcTextBox.onkeydown
     added codes for createing rectangle and group it with the pin and text

3. In makeTags function
    Added text.data.home = tagText; // data.home is a proper for PointText
   Commented out //text.visible = false;  // once the user input a string, the string will show up right away