make the modified 2p2c(ni) models run and rename them to new_2p2c(ni)

also, restore the 2p2c(ni) models to their previous state.in order to
compile the new_2p2c(ni) tests, you have to set symbolic links to the
devel repository for the following the direcories

dumux/material/fluidstates
dumux/material/new_fluidsystems
dumux/material/eos
dumux/material/constraintsolvers

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@5335 2fb0f335-1f38-0410-981e-8018bf24f1b0