Added tab-based interface to userpage UI. Yes, it is plugin expansible, and yes, it breaks existing plugins that add code to the userpage (but that can be fixed with a "colspan=4")

.panel_wrapper {height:85px;}
.panel_wrapper div.current {height:85px;}

/* IE */
* html .panel_wrapper {height:100px;}
* html .panel_wrapper div.current {height:100px;}