Catalyst Crosscompiling and Revamp

Allow cross-compiling Gentoo stages and boot media for other architectures in a robust manner, with increased security and reliability. This will be done through the use of efficient virtualization offered by QEMU, which allows booting into the stage tarballs and running scripts to finalize the image that is traditionally done from a chroot context. Work will also be done to set various defaults based on the configuration of the machine catalyst is running on if unspecified. I will write a comprehensive guide on how to use Catalyst.