Why do I have 2 Maya folders after loading "Extension 2" on Mac. I now have "maya2013" and "maya2013.5" in my Autodesk folder in Applications. Also, I've noticed some of my previous plugins from "maya2013" are not showing up in "maya2013.5". Whats the difference between an "Extension" and a "Service Pack"? Can I just drag my plugins from "maya2013" into "maya2013.5"? Are both folders necessary?