Updating GIS.txt file formats in demo, changing reading of dat files to only search for files ending in .dat (rather than files with ".dat" in filename).  Similar for GIS.txt files.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/qfa@627 edb9625f-4e0d-4859-8d74-9fd3b1da38cb