prevent some session deadlock errors.
* Fixed some bugs with the new auto-resizing toolbar:
* In IE 6/7, when you click on a formatting button such as italics, it
doesn't visibly depress, because update_toolbar() is causing it to
unpress until you start typing the italic text. Fixed by only calling
update_toolbar() in focused_editor() if focused_editor is null.
* When downing or upping a toolbar button, now calling
resize_toolbar_button() unconditionally.