Fix custom date format on DateTimePicker.

Custom date format was not working properly on datetime_picker due to a missing option 'formatSubmit' on the $dateOptions array.

EDIT: Added missing default options 'todayButton', 'todayHighlight', 'clearButton' and specially 'language' (because it was preventing the translation of the calendar widget) on DateTimePickerType. These are options already available on DatePickerType.