included BoundaryVariables in boxproperties - neccessary for outflow

boundary conditions. This is not used in the current models in the
stable branch, but needed for the coupled models and the stokes models


git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@5206 2fb0f335-1f38-0410-981e-8018bf24f1b0

dumux/boxmodels/common/boxproperties.hh

@@ -75,6 +75,7 @@ NEW_PROP_TAG(ElementSolutionVector); //!< A vector of primary variables within a
 NEW_PROP_TAG(VolumeVariables);  //!< The secondary variables within a sub-control volume
 NEW_PROP_TAG(ElementVolumeVariables); //!< The secondary variables of all sub-control volumes in an element
 NEW_PROP_TAG(FluxVariables); //!< Data required to calculate a flux over a face
+NEW_PROP_TAG(BoundaryVariables); //!< Data required to calculate fluxes over boundary faces (outflow)
 
 // high level simulation control
 NEW_PROP_TAG(TimeManager);  //!< Manages the simulation time