Adjusted the documentation of the CO2 models and tests according to FS#209.
git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@12615 2fb0f335-1f38-0410-981e-8018bf24f1b0
git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@12615 2fb0f335-1f38-0410-981e-8018bf24f1b0