Add 'editing disable' loader option to globally disallow option editing.
Add 'editing disable' loader option to globally disallow option editing.

aaronp24/gummiboot,miguelinux/gummiboot2systemd-boot,trilean/gummiboot,trilean/gummiboot,freedesktop-unofficial-mirror/gummiboot,freedesktop-unofficial-mirror/gummiboot,aaronp24/gummiboot,miguelinux/gummiboot2systemd-boot