Added check for new Debian system (prog5) when configuring Xalan make...

Added check for new Debian system (prog5) when configuring Xalan make variables. This change was needed to allow the Debian system to build our documentation. References #338.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@3242 41f8697f-d340-4b68-9986-7bafba869bb8