Added a script to run all the unit tests.

Install m-unit-tests module from Github/master if needed.

tests/runalltests.m

+opath = path();
+
+% Check that the m-unit-tests module is available.
+
+install_unit_test_toolbox = false;
+
+try
+    initialize_unit_tests_toolbox;
+catch
+    urlwrite('https://github.com/DynareTeam/m-unit-tests/archive/master.zip','master.zip');
+    warning('off','MATLAB:MKDIR:DirectoryExists')
+    mkdir('../externals')
+    warning('on','MATLAB:MKDIR:DirectoryExists')
+    unzip('master.zip','../externals')
+    delete('master.zip')
+    addpath([pwd() '/../externals/m-unit-tests-master/src'])
+    initialize_unit_tests_toolbox;
+    install_unit_test_toolbox = true;
+end
+
+% Initialize the dseries module
+try
+    initialize_dates_toolbox;
+catch
+    unit_tests_root = strrep(which('runalltests'),'runalltests.m','');
+    addpath([unit_tests_root '../src']);
+    initialize_dates_toolbox;
+end
+
+tmp = dates_src_root;
+tmp = tmp(1:end-1); % Remove trailing slash.
+run_unitary_tests_in_directory(tmp);
+
+delete('*.log');
+
+if install_unit_test_toolbox
+    rmdir('../externals/m-unit-tests-master','s');
+end
+path(opath);
\ No newline at end of file