Admin Panel CSS is loaded in the Backend
Since the admin panel CSS is at t3skin/visual/admin_panel.css, it is loaded with every backend request. Obviously, the admin panel is not needed in the backend so its a bit of a waste to load it.
In addition, the CSS has a strange issue that it interferes with resizable text areas in Chrome 9 (as described on #24744).
Moving the admin panel CSS to t3skin/standalone/admin_panel.css ensures that it is not loaded automatically by the backend.
(issue imported from #M17302)