Rewrote double function.

Also changed unit tests. The syntax qq = dates('Q'); qq(1950,1) does not
work anymore, most likely because of inplace modifications...

src/@dates/double.m

-function [B, C]  = double(A) % --*-- Unitary tests --*--
+function [m, f]  = double(o) % --*-- Unitary tests --*--
 
 % Returns a vector of doubles with the fractional part corresponding
 % to the subperiod. Used for plots and to store dates in a matrix.
 %
 % INPUTS 
-%  o A     dates object.
+% - o [dates]
 %
 % OUTPUTS  
-%  o B     A.ndat*1 vector of doubles.
-%  o C     integer scalar, the frequency (1, 4, 12 or 52).
+% - m [double] o.ndat*1 vector of doubles.
+% - f [integer] scalar, the frequency (1, 4, 12 or 52).
 %
 % REMARKS 
 %  Obviously the frequency is lost during the conversion.
-    
-% Copyright (C) 2013 Dynare Team
-%
-% This file is part of Dynare.
+
+% 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.
@@ -30,15 +28,14 @@ function [B, C]  = double(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/>.
 
-B = A.time(:,1)+(A.time(:,2)-1)/A.freq;
+m = o.time(:,1)+(o.time(:,2)-1)/o.freq;
 if nargout>1
-    C = A.freq;
+    f = o.freq;
 end
 
 %@test:1
 %$ % Define a dates object
-%$ qq = dates('Q');
-%$ B = qq(1950,1):qq(1951,1);
+%$ B = dates('1950Q1'):dates('1951Q1');
 %$
 %$ % Call the tested routine.
 %$ try
@@ -58,14 +55,11 @@ end
 %@eof:1
 
 %@test:2
-%$ % Define a dates object
-%$ qq = dates('Q');
-%$
 %$ % Call the tested routine.
 %$ try
 %$     C = NaN(2,1);
-%$     C(1) = double(qq(1950,1));
-%$     C(2) = double(qq(1950,2));
+%$     C(1) = double(dates('1950Q1'));
+%$     C(2) = double(dates('1950Q2'));
 %$     t(1) = 1;
 %$ catch
 %$     t(1) = 0;