Fixed hard-to read line breaks in 2p2c folder introduced by commit 12427 to...

Fixed hard-to read line breaks in 2p2c folder introduced by commit 12427 to reduce excessive file lengths.

Prepare variableclassadaptive for 3D mpfa: correcting vector/matrix lengths to work with 2D & 3D, add storage and acess-functions for 3D mpfa data.
reviewd by Christoph

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@12452 2fb0f335-1f38-0410-981e-8018bf24f1b0