Refactor date range directive to match the current system of directives.

frontend/app/ui_components/index.js

@@ -46,9 +46,6 @@ angular.module('openproject.uiComponents')
   .directive('opTime', ['TimezoneService', require('./date/time-directive')])
   .directive('opDateTime', ['$compile', 'TimezoneService', require('./date/date-time-directive')])
   .directive('emptyElement', [require('./empty-element-directive')])
-  .directive('opDateRangePicker', ['TimezoneService', 'ConfigurationService', 
-             'I18n', '$timeout', 'WorkPackageFieldService',
-             'EditableFieldsState', 'Datepicker', require('./date/date-range-picker-directive')])
   .constant('ENTER_KEY', 13)
   .directive('executeOnEnter', ['ENTER_KEY', require(
     './execute-on-enter-directive')])

frontend/app/work_packages/models/index.js

@@ -28,4 +28,5 @@
 
 angular.module('openproject.workPackages.models')
   .factory('WorkPackageAuthorization', require('./work-package-authorization'))
-  .factory('Datepicker', ['TimezoneService', 'ConfigurationService', '$timeout', require('./datepicker.js')])
+  .factory('Datepicker', ['TimezoneService', 'ConfigurationService', 
+                          '$timeout', require('./datepicker.js')]);