pyfll: grub kernels.cfg refactor writing to lines to make readable
packages.d/essential: no more per arch, one set of grub for them all (for now anyway)
Revert "grub: add menus to unset from, fromiso or bootarch"

This reverts commit 7eba64ad8e4c74f236f6f1565e2cb256119d642d.
grub.cfg: defer insmod all_video until we have loadfont and set gfxmode
grub.cfg: only do all setup once
grub.cfg: no-op fixup whitespace after 8132d719
add trial grub_theme support