Remove killprocs support

killprocs was a legacy feature only put in to stop games like Xonotic from
being played on the network, but is only really applicable for certain domains,
not a general case
Modify Karoshi script references into relative paths

Use $PATH to locate Karoshi scripts, such as manage-flags or set_location.
Scripts are symlinked into /usr/bin as 'karoshi-<script>', with any underscores
converted into dashes to ensure consistency