Merge pull request #1302 from asarium/fix/openglInitError

Extend display device initialization error

Author: niffiwan

code/graphics/opengl/gropengl.cpp

@@ -1462,7 +1462,10 @@ bool gr_opengl_init(std::unique_ptr<os::GraphicsOperations>&& graphicsOps)
 	graphic_operations = std::move(graphicsOps);
 
 	if ( opengl_init_display_device() ) {
-		Error(LOCATION, "Unable to initialize display device!\n");
+		Error(LOCATION, "Unable to initialize display device!\n"
+		      "This most likely means that your graphics drivers do not support the minimum required OpenGL version which is %d.%d.\n",
+			  (MIN_REQUIRED_GL_VERSION / 10),
+			  (MIN_REQUIRED_GL_VERSION % 10));
 	}
 
 	// Initialize function pointers