title: simple window without titlebar
body: <p>Good afternoon everyone!  I have been working on a project that requires a basic window without a titlebar.  After browsing a bit on the web I came across this post <a href="https://stackoverflow.com/questions/31002962/create-window-without-title-bar">create window without titlebar</a> with a reply mentioning the use of the "_NET_WM_WINDOW_TYPE_DOCK" atom.  I attempted to create one in my project using the following code:</p>
  
  <pre><code>Display* d = fl_display;
  XWindow w = XCreateSimpleWindow(d, RootWindow(d, fl_screen),
      0, 0,
      400, 100,
      0,
      0x000000, 0x000000);
  
  Atom window_type = XInternAtom(d, "_NET_WM_WINDOW_TYPE", False);
  long value = XInternAtom(d, "_NET_WM_WINDOW_TYPE_DOCK", False);
  XChangeProperty(d, w, window_type, XA_ATOM, 32, PropModeReplace, (uchar*) &amp;value, 1);
  </code></pre>
  
  <p>The window does show, but it still has a titlebar.  I have found several other resources around the web, but I can't get this to stop showing the titlebar.  I do realize that the referenced post is using XCreateWindow, but shouldn't atoms work on XCreateSimpleWindow too.  Any help would be appreciated!</p>
  
  <p>Thanks</p>