Date picker fix

gistfile1.md

line 1 of date-picker.hbs, change placeholder to YYYY.

{{input class="datepicker" placeholder="MM/DD/YYYY"}}

line 54/55 of date_picker_component.js, update format to YYYY and add new parseFormat

format: "MM/DD/YYYY",
parseFormat: ["MM/DD/YY", "MM/DD/YYYY"],

line 417 of pickday.js, change opts.format to opts.parseFormat

date = moment(opts.field.value, opts.parseFormat);