Ok, I finally found a way to have the edit button only show up for the user who wrote the post and the moderator of that forum. If you are not a moderator of the forum, you will not see the edit button unless it is your post. First of all, you need to install Logician's Dynamic Template hack. Once that is installed, go to your "postbit" template and enter the code like this and viola!
Code:
[[((ismoderator($thread['forumid'])) or $post[userid]==$bbuserinfo[userid])]]
$post[editpost]
[[/((ismoderator($thread['forumid'])) or $post[userid]==$bbuserinfo[userid])]]
[high]NOTE:[/high] Admins and Supermoderators will see the edit button at all times, since they are usually allowed to edit all posts.