Merged the three report/reportStream methods into a single one

... with appropriate default parameters.  This leads to slightly
simpler code.  Note though that the method reportStream has
disappeared, and hence this patch may break some code.
I think that's acceptable, though, because the fix is trivial
and the reportStream method never appeared in a release.

[[Imported from SVN: r6302]]

dune/common/parametertree.cc

@@ -17,17 +17,7 @@ using namespace Dune;
 ParameterTree::ParameterTree()
 {}
 
-void ParameterTree::report() const
-{
-  report("");
-}
-
-void ParameterTree::report(const std::string prefix) const
-{
-  reportStream(std::cout, prefix);
-}
-
-void ParameterTree::reportStream(std::ostream& stream, const std::string& prefix) const
+void ParameterTree::report(std::ostream& stream, const std::string& prefix) const
 {
   typedef std::map<std::string, std::string>::const_iterator ValueIt;
   ValueIt vit = values.begin();
@@ -42,7 +32,7 @@ void ParameterTree::reportStream(std::ostream& stream, const std::string& prefix
   for(; sit!=send; ++sit)
   {
     stream << "[ " << prefix + sit->first << " ]" << std::endl;
-    (sit->second).report(prefix + sit->first + ".");
+    (sit->second).report(stream, prefix + sit->first + ".");
   }
 }
 

dune/common/parametertree.hh

@@ -83,20 +83,6 @@ namespace Dune {
     const std::string& operator[] (const std::string& key) const;
 
 
-    /** \brief print structure to std::cout
-     */
-    void report() const;
-
-
-    /** \brief print distinct substructure to std::cout
-     *
-     * Prints all entries with given prefix.
-     *
-     * \param prefix for key and substructure names
-     */
-    void report(const std::string prefix) const;
-
-
     /** \brief print distinct substructure to stream
      *
      * Prints all entries with given prefix.
@@ -104,8 +90,8 @@ namespace Dune {
      * \param stream Stream to print to
      * \param prefix for key and substructure names
      */
-    void reportStream(std::ostream& stream,
-                      const std::string& prefix = "") const;
+    void report(std::ostream& stream = std::cout,
+                const std::string& prefix = "") const;
 
 
     /** \brief get substructure by name