core: drop support for old per-distro configuration files for console, hostname, locale, timezone

This simplifies the upstream system code quite a bit. If downstream distributions want to maintain compatibility with their old configuration files, they are welcome to do so, but need to maintain this as patches downstream. The burden needs to be on the distributions to maintain differences here. Our suggestion however is to just convert the old configuration files on upgrade, as multiple distributions already do.
build-sys: make rc-local support part of SYSV compat

This also drops automatic selection of the rc local scripts
based on the local distro. Distributions now should specify the paths
of the rc-local and halt-local scripts on the configure command line.
Make gcc a bit quieter
fsck: remove distro specific hacks from fsck/quotacheck

Move forcefsck file checks under a HAVE_SYSV_COMPAT #ifdef, and warn if this is used.
systemctl: enable chkconfig compat only if chkconfig is found rather than based on distro
units: drop distro specific stuff from units

Since rc-local is now enabled via the SysV compatibility we should only refer
to it based on that too.
units: always use sulogin in rescue.service

sushell makes much less sense than sulogin. If distros want to stick to sushell
they should patch this downstream.
service: drop the per-distro ifdefs in service.c

They don't really hurt on other distros, and this allows us to ship
the same code on all distros
service: drop inserv.conf parsing

This Suse specific configuration file should really be done in a generator
that is shipped downstream by suse.
build-sys: make path of loadkeys/setfont configurable in configure
build-sys: drop all distribution specfic checks

Yay, we now have a completely generic systemd. No distribution specific checks anymore!