fix the build for non-selinux systems

The symlinks should be created only if MKSELINUX=yes, not if it just has
a value.
Add service applet

The service applet is equivalent to rc-service. This was added so that
we will be more compatible with Debian and Fedora.

Reported-by: cardoe@gentoo.org
X-Gentoo-Bug: 468168
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=468168
fix setfont detection in early startup on Linux

Most of the time, setfont is an external command (part of the kbd
package), but it can also be a builtin if busybox is being used. This
corrects the test in early startup to work for both cases. I would like
to thank Steve L. for pointing this out.
Document busybox applet incompatibilities

Reported-by: slong@rathaus.eclipse.co.uk
X-Gentoo-Bug: 468396
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=468396
Fix wrong wording in STYLE
fix cgroup cleanup bugs.

1). fix incorrect variable assignment in cgroup_get_pids
2). fix calling rc_cgroup_cleanup on start