Add WINGs tutorial

The original website is
http://www.quantitativefinanceservices.com/OpenDir/WINGslib/WINGToc.html

and it had the following notice at the bottom:

Copyright (c) 2010 Permission is granted to copy, distribute and/or modify
this document under the terms of the GNU Free Documentation License, Version
1.1 or any later version published by the Free Software Foundation; with no
Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A
copy of the license is included in the section entitled "GNU Free
Documentation License".

So we are fine.

WINGs_tutorial/SecondWindow.c

@@ -0,0 +1,34 @@
+void closeAll(WMWidget *self,void *data){
+  fprintf(stderr,"I've been used!\n");
+  WMDestroyWidget(self);
+  exit(0);
+}
+
+int main (int argc, char **argv){
+
+ Display *display;
+ WMScreen *screen;
+
+ WMWindow *win;
+ WMColor *color;
+
+ WMInitializeApplication("SecondWin", &argc, argv);
+
+ if (!(display = XOpenDisplay(""))){
+   fprintf(stderr, "cannot open display\n");
+   exit(1);
+ }
+ screen = WMCreateScreen(display, DefaultScreen(display));
+
+ win = WMCreateWindow(screen, "");
+ WMSetWindowCloseAction(win, closeAll, NULL);
+ color = WMCreateRGBColor(screen,124<<9,206<<8,162<<8, False);
+ WMSetWidgetBackgroundColor((WMWidget *)win, color);
+
+ WMMapWidget(win);
+ WMRealizeWidget(win);
+
+ WMScreenMainLoop(screen);
+
+return 0;
+}