regularized van Genuchten: start regularization at 1%

somebody changed it to 10^-6 which is clearly too small. I added a
comment which hopefully can not be overlooked.

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@4067 2fb0f335-1f38-0410-981e-8018bf24f1b0

dumux/material/fluidmatrixinteractions/2p/regularizedvangenuchtenparams.hh

@@ -49,21 +49,43 @@ public:
      * \brief Threshold saturation below which the capillary pressure
      *        is regularized.
      *
-     * This is just 5%. If you need a different value, overload this
+     * This is just 1%. If you need a different value, overload this
      * class.
      */
     Scalar pCLowSw() const
-    { return 5e-6; }
+    { 
+        // Some problems are very sensitive to this value
+        // (e.g. makeing it smaller might result in negative
+        // pressures), if you change it here, you will almost
+        // certainly break someone's code!
+        //
+        // If you want to use a different regularization threshold,
+        // overload this class and supply the new class as second
+        // template parameter for the RegularizedVanGenuchten law!
+        return /* PLEASE DO _NOT_ */ 1e-2; /* CHANGE THIS VALUE. READ
+                                            * COMMENT ABOVE! */
+   }
 
     /*!
      * \brief Threshold saturation above which the capillary pressure
      *        is regularized.
      *
-     * This is just 95%. If you need a different value, overload this
+     * This is just 99%. If you need a different value, overload this
      * class.
      */
     Scalar pCHighSw() const
-    { return 1-5e-6; }
+    {
+        // Some problems are very sensitive to this value
+        // (e.g. makeing it smaller might result in negative
+        // pressures), if you change it here, you will almost
+        // certainly break someone's code!
+        //
+        // If you want to use a different regularization threshold,
+        // overload this class and supply the new class as second
+        // template parameter for the RegularizedVanGenuchten law!
+        return /* PLEASE DO _NOT_ */ 99e-2; /* CHANGE THIS VALUE. READ
+                                             * COMMENT ABOVE! */
+    }
 
     /*!
      * \brief Threshold saturation below which the relative