Rewrote unique function.

src/@dates/unique.m

-function B = unique(A) % --*-- Unitary tests --*--
+function o = unique(o) % --*-- Unitary tests --*--
 
 % Overloads the unique function for dates objects.
 %
 % INPUTS 
-%  o A    dates object.
+% - o [dates]
 %
-% OUTPUTS 
-%  o B    dates object (a copy of A without repetitions, only the last occurence of a date is kept).
-
-% Copyright (C) 2012-2013 Dynare Team
+% OUPUTS 
+% - o [dates]
 %
-% This file is part of Dynare.
+% REMARKS 
+% 1. Only the last occurence of a date is kept.
+
+% Copyright (C) 2013-2014 Dynare Team
 %
-% Dynare is free software: you can redistribute it and/or modify
+% This code is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 %
-% Dynare is distributed in the hope that it will be useful,
+% Dynare dates submodule is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -25,20 +26,18 @@ function B = unique(A) % --*-- Unitary tests --*--
 % You should have received a copy of the GNU General Public License
 % along with Dynare.  If not, see <http://www.gnu.org/licenses/>.
 
-if isequal(A.ndat,1)
+if o.ndat<=1
     return
 end
 
-B = A;
-
 if isoctave || matlab_ver_less_than('8.1.0')
-    [tmp, id, jd] = unique(A.time,'rows');
+    [tmp, id, jd] = unique(o.time,'rows');
 else
-    [tmp, id, jd] = unique(A.time,'rows','legacy');
+    [tmp, id, jd] = unique(o.time,'rows','legacy');
 end
 
-B.time = A.time(sort(id),:);
-B.ndat = size(B.time,1);
+o.time = o.time(sort(id),:);
+o.ndat = size(o.time,1);
 
 %@test:1
 %$ % Define some dates