Dialog: Don't handle overlays on destory if there are not any. Fixed: #9004 - failed in _destroyOverlay when I destroy a modal dialog thau was never opened. Fixed: #9000 Dialog leaves broken event handler after close/destroy in certain cases
Autocomplete demo: Fixed reference to widget instance.
Dialog: Allow interaction with datepickers from modal dialogs. Fixes #8989 - Dialog: Cannot change month/year in datepicker within modal.
Dialog: modified _createOverlay to _appendTo instead of document.body. Fixed #8984 - Modal dialogs display behind overlay when using appendTo option