Made time conversion functions publicly accessible

[andyuk]

Hi,

It's useful to be able to use the timePicker functions to be able to convert between the different time formats. I've exposed 2 private functions in this pull request.

The jQuery UI datepicker works in a similar way (http://docs.jquery.com/UI/Datepicker/formatDate and http://docs.jquery.com/UI/Datepicker/parseDate).

Thanks, Andrew