Added for EFI only (see stage1/scripts.d/01-grub).

Also:
- added new target jeos-systemd,
- disabled quiet for cmdline kernel
- returned to its original form regular-jeos-ovz

Do not create syslinux.cfg if EFI_BOOTLOADER is set to not equal grub-efi.

These are partial commits reverts:
01ee4075
e42bcdcb
5cfc7ede

This is necessary to prevent unintentional assignment of rEFInd
as EFI_BOOTLOADER.
I also want to hope that memtest86.efi can be made to work from
grub-efi in the future.

The word "ALT" already contained in @relname@.
Added when call use/grub.

These changes allow you to create two independent config at the same
time or separately. It will be possible to add support for grub-pc in
the future.

The definition of the default menu item has been fixed.
Grub.cfg does not use label, uses --id.
It is assumed that --id is given last.

Not needed Stage1 package. They are added to mkimage.

The scripts were named the same for syslinux and grub. Because of this,
scripts for syslinux were overwritten by grub scripts.

NetworkManager not worked without udev-rule-generator-net on sysvinit

Many applications need a gnome-icon-theme.

Reported-by: Speccifighter
See-also: https://forum.altlinux.org/index.php?topic=42738.msg344544#msg344544

See-also: https://lists.altlinux.org/pipermail/devel/2019-December/209313.html

See-also: commit e4bb1727

See-also: https://forum.altlinux.org/index.php?topic=43385.msg345596#msg345596

Needed for running installer.

Reported-by: Speccifighter
See-also: https://forum.altlinux.org/index.php?topic=42738.msg344544#msg344544

Нужно признать, что grub станларт, которму мы должны соответствовать.
а поддержка efi у нас полноценна пока только в refind.

Also added explicit call +sysvinit or +systemd for server targets.
Users also want to start the server on systemd.
in addition to on aarch64 in qemu, the shell does not start on the
serial console for sysvinit. This is critical for non-desktop builds.