Change Linux 2.2 instructions to install from tun-1.0-1.i386.rpm,
since tun-1.0.tar.gz is no longer available from sourceforge.
Improve explanation of hercifc setuid security considerations.
Add "what to do if it doesn't work" section.
git-svn-id: file:///home/jj/hercules.svn/trunk@578 956126f8-22a0-4046-8f4a-272fa8102e63