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

See ALT bug 31971

All drm modules are added to the first and second stages, except
for nouveau and nvidia. Nouveau is added to stage2. nvidia needs
to be added to live and the base system separately. This is an
auxiliary target.

See also https://bugzilla.altlinux.org/31971

See https://bugzilla.altlinux.org/45792

The installer works more reliable when loaded to RAM.

evms fails to stop a RAID if a RAID is removed and a new one
is created in its place. The problem appeared after we added
mdadm to altinst.
Reported by mcpain@
NOTE: The problem is not observed in live. Either something is
removed from altinst, or something is not installed.

x11vnc doesn't work when xvt calls a terminal other than xterm.
This is a regression in xinit. Does not work any more:

  xinit <command>

Only:

  xinit -e <command>

But they are not going to fix it.
See also: https://bugzilla.altlinux.org/45574