Scaled up 2D codes to prevent blurriness

If you generate a QR code with a short content string, the resulting image will have small dimensions.

For instance, I generated a code using a 20 character string as content, and the image returned was 27x27 pixels. I wanted to display it on a 300x300 view, so it ended up very blurred.

To prevent it, all the 2D codes are now scaled by a factor of 15x. This way, the image will be downscaled when shown, and the quality will be preserved.

Here's a before and after comparison: http://cl.ly/image/3W0k2F2k181F