getLayout ignores padding for width (e.g. for autocomplete fields)

[jensb]

See https://jsfiddle.net/3jpgtm4v/:
the width of the autocomplete DIV is calculated incorrectly if the input field has padding applied to it.
Padding should be duplicated in the autocomplete div if it exists.

Enter a letter (eg 'b') into the example input field at the lower right of the link above to see an example.

[jensb]

Oops. That would be a scriptaculous bug I guess. Sorry.