works with and without randomfields and geor

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/diseasemapping@812 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
should work without rgdal

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/diseasemapping@813 edb9625f-4e0d-4859-8d74-9fd3b1da38cb