title: cancel button not displayed for wizard page created with wpInfoAfter in inno setup
body: <p>I have created a custom wizard page in inno, which needs to be shown after installing the files to {app} folder. This is achieved by giving the wpInfoAfter. 
  The problem is, its showing only the 'next' button, there is no cancel/back button, also the dialog's closing button on top right is also disabled. I understand that the back button isn't needed, as it needs to remove the files which are installed. Is there anyway the 'cancel' button can be displayed?</p>