Inline - getDate - TypeError: Cannot read property 'datepicker' of undefined

In _create function variable calendar is a function variable so this.calendar is undefined

I think this

```
this.baseWidget = ( !this.options.inline )? this.element: this.calendar;
```

must be replaced with this

```
this.baseWidget = ( !this.options.inline )? this.element: calendar;
```
