moved from devel: a meshcreator which gradually refines towards the (free flow - porous medium) interface

dumux/io/plotoverLine2d
moved from devel: a class for plotting variables between two (user-specified) points. Values are written to a *.dat file, that can be read in by an external plotting tool

dumux/dumx/common/dimensionlessnumbers
moved from devel: a class for calculating dimensionless numbers (Reynolds, Prandtl, ...) 

reviewed by Bernd


git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@11056 2fb0f335-1f38-0410-981e-8018bf24f1b0