With directory layout differences between Red Hat, Debian, Suse and
other distros one needs to set the variables for the elements below

-----------------+------------------+---------------+----------------+
                 | Red Hat          |  Debian       |  Suse          |
-----------------+------------------+---------------+----------------+
CONFIG_LEAF_DIR  | sysconfig        | default       | sysconfig      |
INITD_DIR        | /etc/rc.d/init.d | /etc/init.d   | /etc/init.d    |
-----------------+------------------+---------------+----------------+

The existence of these directories are tested at build-time (on the
build host, via the "setvar_dir" macro in Config.mk) and for some
scripts at run-time.  If the Red Hat directory exists, it is used;
otherwise the Debian one is used.

The INITD_DIR path can be changed with configure --with-initddir=DIR.
The CONFIG_LEAF_DIR name can be changed with configure
--with-sysconfig-leaf-dir=SUBDIR.

To add support for new distributions that don't use the above locations,
one must grep for the above elements and add appropriate checks.

For example if a new distro uses /etc/bork as its config dir, it's not
sufficient to set CONFIG_LEAF_DIR=bork; one must also add tests for the
existence of the bork dir in every context where config files are read.