Wiki update for readline / 1.9.0

I’ve just updated the Mothur wiki with a couple of packages I needed to install to get Mothur to install on Redhat. I also updated the entry for Ubuntu with the equivalent packages, but I don’t have an Ubuntu PC to check. Can someone running Ubuntu cast their eyes over http://www.mothur.org/wiki/Installation#Linux.2FUnix and make sure my additions are sane. :slight_smile: