Upgrade jQuery timepicker to 1.3
Enable JS date/time formats to be controlled

This commit provides two mechanisms for passing format information from
Django to JS.

1. An options object can be passed to the oscar.dashboard.init method
   that provides default values for the formats.  This is optional - the JS
   itself has some hard-coded defaults.

2. Form elements can defined data attributes that specify format
   information directly.  This is implemented for the datetime inputs
   within the offers dashboard.
Introduce new widgets that pick up locale date formats