- further unification of cc files: the Gridcreator property is now set in the problem file

-> gridcreator standard is dgf, if the gridcreator property is reset, grid dimensions are specified in input file (test/boxmodels/2pni, test/decoupled/1p)
-> in the cc: first include the gridcreator file, then the problem
- removed some includes from cc files

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@7731 2fb0f335-1f38-0410-981e-8018bf24f1b0