A two way knockout date binder
bind and format a date string to a html element
requires date.js -> http://www.datejs.com/
binding options
date date value as string in viewmodel
dateFormatModel [optional] date format in viewmodel (default: iso 8601 format -> yyyy-MM-ddTHH:mm:ss)
dateFormatView [optional] date format to display (default: dd.MM.yyyy)
dateBindTo [optional] bind to html element property (default: value)
useage
<input data-bind="date: Field" />
<span data-bind="date: Field, dateBindTo: 'text', dateFormatView: 'dd.MM.yyyy HH:mm'"></span>
by M. Winkler