Fix all domtool scripts for modern Debian and HCoop practices

Fix all domtool scripts for modern Debian and HCoop practices
* There is no longer any local `domtool' group, use `nogroup' instead and
  chmod files user readable only
* The init scripts assumed `/usr/local/[s]bin' were in `$PATH', which
  is not true on a default Debian install. Rather than require
  customization of system defaults, just use long paths. It would be
  nice if the Makefile supported relocatable installs, but I also want
  a pony for xmas.
* `domtool-admin-sudo' never worked properly. It seems to rely on the
  mistaken assumption that starting a `pagsh' gives you a new
  PAG... when `pagsh' has the unintuitive behavior of adopting the
  current PAG instead of creating a new one if one should
  exist. Things appeared to work since there was always a local
  domtool user, and some interaction between the init scripts
  acquiring tokens outside of a PAG and sudo led to use of the uid
  ticket cache. The solution is just to use `k5start' instead of
  `kinit && aklog'