Make BenchmarkDemo a console application, without OpenGL/Glut dependency.

Fix potential division by zero when enabling convex distance utility.
Thanks to linzner http://code.google.com/p/bullet/issues/detail?id=264

Demos/OpenGL/GlutStuff.cpp

@@ -70,7 +70,7 @@ static void glutDisplayCallback(void)
 	gDemoApplication->displayCallback();
 }
 
-#ifndef _WINDOWS
+
 int glutmain(int argc, char **argv,int width,int height,const char* title,DemoApplication* demoApp) {
     
 	gDemoApplication = demoApp;
@@ -104,4 +104,4 @@ int glutmain(int argc, char **argv,int width,int height,const char* title,DemoAp
     return 0;
 }
 
-#endif //_WINDOWS
+