boundaryId had wrong name

[[Imported from SVN: r3063]]

grid/onedgrid/onedintersectionit.hh

@@ -147,7 +147,7 @@ namespace Dune {
     int level () const {return center_->level_;}
 
     //! return information about the Boundary
-    int boundaryEntity () {
+    int boundaryId () {
 #warning please implement a course grid boundary segment id
       return 0;
     }