Currently, My iMac is on Mavericks 10.9.5. When Yosemite was first available, I downloaded the installer (10.10.0) but did not install. Now 10.10.1 becomes available and I am considering direct upgrade to 10.10.1 from Mavericks. Do I need to upgrade to 10.10.0 first then to 10.10.1? Is the 10.10.1 from Apple Store a complete installer?