Summary of Update: This additional enhancement will allow for an icon to display beside the text of the Signup/login button.
If you've already added this resource simply paste the following into your EXTRA.CSS template and upload the signup_icon.png into your /gradients folder. (download for the icon below in attachment)
For those of you that haven't installed this, you will need to add the image/code (below) and revert to the release thread as well and add the code/image from there also.