Now lvm and cryptsetup are required not only in the
installed system, but also in altinst. This is because the remount
happens before the base system is installed.

wi-fi may also need to be configured in the installer.

This reverts commit 1076d79f.

The only workable xvt is xterm, since only works with it:

  xinit cmd

See commit: 2451a17c

Requested by Ivan A. Melnikov <iv@altlinux.org>

Use a prebuilt grub image for EFI, creating BOOT/EFI/grub.cfg

See ALT bug 31971