A bootable installer is one of the fastest ways to install Mavericks. Rather than copy the installer to a local drive you can run it right off a USB disk (or Thunderbolt if you dare). Such a little USB drive would be similar to the sticks that came with the older MacBook Air, when we were all still sitting around wondering how you would ever install the OS on a computer with no optical media or Ethernet otherwise. Luckily, Apple loves us. To make a bootable USB/flash drive of Mavericks like the one that used to come with the MacBook Air, first name the USB drive. I’ll use mavinstall for…