Fix size of M_.endo_histval.

Should fix crashes on models with leads/lags of more than one on exogenous.

Closes #617

preprocessor/NumericalInitialization.cc

 /*
- * Copyright (C) 2003-2013 Dynare Team
+ * Copyright (C) 2003-2014 Dynare Team
  *
  * This file is part of Dynare.
  *
@@ -269,7 +269,7 @@ HistValStatement::writeOutput(ostream &output, const string &basename) const
   output << "%" << endl
          << "% HISTVAL instructions" << endl
          << "%" << endl
-         << "M_.endo_histval = zeros(M_.endo_nbr,M_.maximum_lag);" << endl;
+         << "M_.endo_histval = zeros(M_.endo_nbr,M_.maximum_endo_lag);" << endl;
 
   for (hist_values_t::const_iterator it = hist_values.begin();
        it != hist_values.end(); it++)
@@ -305,7 +305,7 @@ HistValStatement::writeOutput(ostream &output, const string &basename) const
       int tsid = symbol_table.getTypeSpecificID(symb_id) + 1;
 
       if (type == eEndogenous)
-        output << "M_.endo_histval( " << tsid << ", M_.maximum_lag + " << lag << ") = ";
+        output << "M_.endo_histval( " << tsid << ", M_.maximum_endo_lag + " << lag << ") = ";
       else if (type == eExogenous)
         output << "oo_.exo_simul( M_.maximum_lag + " << lag << ", " << tsid << " ) = ";
       else if (type != eExogenousDet)