change the overflow-y css attribute to hidden whilst the element is expanding or collapsing, if we don't do this then the scrollbar is shown briefly whilst the element is expanding or collapsing when the height of the element is less than the specified max-height value
Added commments and unset overflow-y value instead of explicity setting to auto
Fixed silly bug for the collapse, didnt set overflow-y to hidden
modified to add a class instead of setting explicit css property during animation
Modify to allow the typeahead to go above the input box
Make the updating of the typeahead list more animation friendly