Add 'use strict'.

accountant/frontend/static/js/accounts.js

@@ -15,6 +15,7 @@
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
  */
 // vim: set tw=80 ts=2 sw=2 sts=2:
+'use strict';
 
 accountantApp
 

accountant/frontend/static/js/app.js

@@ -14,6 +14,8 @@
     You should have received a copy of the GNU Affero General Public License
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
  */
+'use strict';
+
 var accountantApp = angular.module("accountantApp", [
     'ngResource', 'ngRoute',
     'mgcrea.ngStrap',

accountant/frontend/static/js/operations.js

@@ -15,6 +15,8 @@
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
  */
 // vim: set tw=80 ts=2 sw=2 sts=2:
+'use strict';
+
 accountantApp
 
 .factory("Operation", [ "$resource", function($resource)  {

accountant/frontend/static/js/scheduler.js

@@ -14,6 +14,8 @@
     You should have received a copy of the GNU Affero General Public License
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
  */
+'use strict';
+
 accountantApp
 
 .factory("ScheduledOperation", ["$resource", function($resource) {