introduce a rudimentary (working) form of the topological sort principle.

We can now start SSH with optional syslogging support. Also, if a program
is not already present in the /etc/rc.d "profile" (actually, not it has become
a collection of profiles) it will be automatically added.

This sounds hackish, and it probably is, but also, it might be the best
workable solution for now...

svn path=/nixpkgs/trunk/; revision=5044