using the token list's offset height (border-box height)...

...instead of its content height in determining where to position the dropdown. Also removing some redundant `$(...)` calls.

Note that [.getBoundingClientRect](https://developer.mozilla.org/en-US/docs/DOM/element.getBoundingClientRect) is supported all the way back to IE4, Firefox 3, Safari 4, and in all Chrome and Opera versions.