Improved support for jQuery Mobile

Performed the following improvements:
- Bug fix for some missing styles (http://jsfiddle.net/2w8xj/)
- Added an auto trigger of parent's 'onChange' event
- Added the ability to change the datepicker format by adding 'date-format' to the parent

You can check the final improvements here: http://jsfiddle.net/3xmH7/

Carlos