Switch to rEFInd on EFI systems

[vKnmnn]

hey @aguslr,

since grub's rendering performance is bad for screens with high resolutions on uefi, and grub menues look really boring, i thought about layering refind on top of your project.

I have started working, using grub-mkstandalone to create an .efi file for each iso present on the stick, since refind cannot boot iso files directly (needs a loopback device implementation for efi).

The obvious limitation here being, that one would have to run a script that renames (enables) efi files when an iso is added or removed. The efi files themselves would only have to be built a single time, or when sources are updated. Each file takes about 12MB now, which sure could be stripped down a bit. We should also be able to reuse the cfg files you already created, but i haven't found out yet, how to put multiple config files into the efi file.

as a plus, refind looks really really nice with a decent theme :)

[vKnmnn]

So, i think I'm pretty much done, should i make a PR, or would you rather organize it via submodule? you can take a look at it at my repos