Make the instructions a bit more blow-by-blow. Re-order them so they
correspond to the Install.unx step numbers. Explicitly refer to
Install.unx and Install.X11 where appropriate.
I'm updating the official binary to be built on a Redhat 8.0 system. This
should give the binary some legs if we take a while to get the next release out.
- forgot to apply this change before making the 3.4.0 binary (it was
actually built using these settings). It's safer for the game itself to be
non-group writable so that someone on a public server can't exploit a
bounds checking or similar error to infect the executable itself with
a trojan horse.
