Color accumulation & refraction/reflection
Finally I got the color accumulation working. The color is accumulated by creating two textures. For the final color in the scene we access the colors from the texture and then render the final color to the texture. That way, we are constantly accessing textures from the previous frame and updating the texture in current frame with the final color.
Refraction & reflection: I used the technique which I described in my CUDA path tracer blog post.
However, I see some problems in it. I don't see any of the shadows. But color bleeding is there. Also, no caustics are visible. Working on it.
Anti alias: For anti aliasing effect, I jittered the camera position for each frame. Subsequently, as the color accumulation take place, I got the anti aliased image.