Added initialization routine and missing routine.

To use this toolbox the src folder should be added to the Matlab's path
and the script src/initialize_unit_tests_toolbox should be executed (if
needed the missing subfolder will be added to the path).

src/initialize_unit_tests_toolbox.m

+% Get the path to the dates/src folder.
+unit_tests_src_root = strrep(which('initialize_unit_tests_toolbox'),'initialize_unit_tests_toolbox.m','');
+
+if ~exist('isoctave','file') 
+    addpath([unit_tests_src_root '/missing/isoctave'])
+end
\ No newline at end of file

src/missing/isoctave/isoctave.m

+function l = isoctave()
+
+% Tests if Octave is used.
+    
+% Copyright (C) 2013-2014 Dynare Team
+%
+% 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 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.
+%
+% You should have received a copy of the GNU General Public License
+% along with Dynare.  If not, see <http://www.gnu.org/licenses/>.
+
+l = exist('OCTAVE_VERSION');
\ No newline at end of file