This change mostly concerns with making icewm flavour
the lean one again.

The goal is to widen the dynamic range of regular image features:
icewm is not a desktop thus can bear withouth systemd-logind
even if a bunch of network-managing-media-mounting crap has been
rigged to depend on it, and ALT domain client should be included
in most builds for convenient testing in SMB environments but can
stay out of this minimal and "different" image.

It also receives the "un-def" kernel flavour (3.8.0 as of today)
which might benefit from the more available testing facility too.

Its branding is also simplified, plain syslinux menu is fine;
in similar vein, refind feature is flipped from icewm-only to
all-but-icewm set of images with its state being good enough
as of refind 0.6.7 and mkimage 0.2.7.