Realname Comment Author Token

When using the RealName module, I ended up needing to create a token for the author of a comment. I ran into this when using the Notifications module.

When using Notifications, the ['realname'] token substitutes in the real name of the person receiving the message. However, I wanted to have the creator of the comment substituted in instead. To do this, I created a new token called ['realname-comment-author']. I'm attaching a patch with my changes. Please let me know if you have any questions.