daterange_picker inserts wrong date

I already mentioned it somewhere, the  daterange_picker inserts a wrong date. Instead of something like '2013-08-11 - 2013-09-11' it inserts '2013-00-11 - 2013-00-11'.

The format should be

```
format:           "yyyy-MM-dd",
```

instead of

```
format:           "yyyy-mm-dd",
```

Also an option to format the date would proof helpful.

Thanks.

/m
