Moved panel-generating visualization functions to separate file graphics.R. Renamed and changed existing functions to adjust for the recent additions in package psychotools.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/prefmod@232 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
See previous commit.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/prefmod@233 edb9625f-4e0d-4859-8d74-9fd3b1da38cb