feat: multiple dialog, drag n' drop, new style

[macmessa]

Adding:

• Multiple modal dialogs;
• Drag and drop;
• Built-in style;
• Possibility to use a function as interface for showModalDialog (see bellow).

function showMaximizedDialog(url, args) {
  // showModalDialog.interface
  var WindowParams = [
    'dialogLeft:0',
    'dialogTop:0',
    'dialogHeight:' + screen.availHeight + 'px',
    'dialogWidth:' + screen.availWidth + 'px'
  ].join(';');

  return window.showModalDialog(url, args, WindowParams);