compare

This is the 1. iteration. The thresholds might have to be adapted for
more tests by knowledgable people

This and the last commit on tests were
reviewed by fetzer


git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@15257 2fb0f335-1f38-0410-981e-8018bf24f1b0