Can't type date in the text input box using keyboard

[sinelaw]

Unlike the original jquery-ui datepicker, it's not possible to type in a date using the keyboard in the text input box.

See working typing in this jquery-ui datepicker demo: http://jqueryui.com/datepicker/

Non-working demo of angular-ui-date: http://angular-ui.github.io/ui-date/

[sinelaw]

The tip of master branch seems to have this partially fixed; there's still an exception thrown when you type in characters. I'm sending a pull request to fix that.