documentation update, added function exception::diagnostic_information, added std::exception to_string overload, removed tabs from source files

[SVN r46697]

include/boost/exception/to_string.hpp

@@ -53,6 +53,20 @@ boost
         {
         enum e { value=to_string_detail::has_to_string_impl<T,is_output_streamable<T>::value>::value };
         };
+
+    template <class T,class U>
+    std::string
+    to_string( std::pair<T,U> const & x )
+        {
+        return std::string("(") + to_string(x.first) + ',' + to_string(x.second) + ')';
+        }
+
+    inline
+    std::string
+    to_string( std::exception const & x )
+        {
+        return x.what();
+        }
     }
 
 #endif