Allows use of an array of date formats

Moment.js allows use of an array of date formats when parsing dates.

This means that you can do... `moment('05/05/1945', ['dd/mm/yyyy', 'dd-mm-yyy'])` and `moment('05-05-1945', ['dd/mm/yyyy', 'dd-mm-yyy'])` and both will work. Moment will keep trying the formats in the array until it finds the correct one to parse it with.

I have updated the date picker to accept an array for the 'format' parameter. It then uses the first format in the array as the display format.
Sorry, @eddielee6, I do not see any new commit in this PR.

I understand the problem, and I am not sure if there are an easy and cheap way to fix it at momentjs side.  

What if we enable strict parsing only for _format_ as array, something like this:

```
if (Object.prototype.toString.call(format) === '[object Array]') {
    mmnt = moment(value, format, true);
} else {
    mmnt = moment(value, format);
}
```