Updated documentation

We've updated the corporate site (http://networkradius.com), so it's a bit prettier. As part of that re-write, we've moved the documentation to using gitbook. It's not perfect, but it's a lot better than it was before. Please check out: http://networkradius.com/doc/current/ It has a nice table of contents, good formatting, and tons of cross-links for each page. We're working on adding more documentation over the next few months, too. Alan DeKok.