switched back the way of getting the index of an intersection in the

discretization of the 2p saturation equation

   - way of getting the index of an intersection was changed for
     use of adaptive grids. However, this only works in the case in which the order of the iteration by 
     the IntersectionIterator coincides with the ordering at the
     reference element (e.g. not valid for UGGrid)
   - Switch back to use indexInInside() function -> Adaptive method will
     not work properly until a better solution is found!



git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@6589 2fb0f335-1f38-0410-981e-8018bf24f1b0