need css id for targetting individual multiselect fields

Issue Summary

I stumbled across this while trying to selectively change the width of one particular multiselect field (while leaving the others alone).

Changing the width of select.multiselect_unsel and select.multiselect_sel works great but leaves the labels (#label_unselected and #label_selected) aligned incorrectly. In navigating up the the tree to grab an id selector on the form-item div, I noticed the typical cck field id is no longer present on multiselect fields. i think this is probably an oversite. I'm trying to grok the code to submit a patch now, but haven't quite figured it out yet.

Also, I just noticed there are several non-unique css ids in multiselect fields-- the above #label_unselected and #label_selected ids are the same for each field and therefore not unique. The same is true for #multiselect_labels and #multiselect_available. afaik, ids must be unique per page.