Feature: Support loading kernels from a distro-controlled partition

As a possible solution to the bootloader issues covered in %Distro-ready and an alternative to linux-wiiu#15 (closed), linux-loader could read its kernel from a traditional /boot partition; formatted as FAT32 or something like that.

This would bring up the question of how to find the kernel's filename, provide a commandline, etc. would work. Something to think about! I'm reluctant to create a custom config format for distros to use, so perhaps parsing grub or yaboot configs could work.