- #268850: fix pencil link for Clear URL.
- add .meta-header and .meta-footer, with different styling.
- update large screenshot.
- add 2nd menu.
- better breadcrumb, search box and mission handling.
- cleanup Left Navigation and Right Subcontent (Layout-1/2/4).
- document Left Subcontent and Right Navigation in custom.example.css (Layout-3/5).
- add placeholder for IE6 hack.
- add placeholder for RTL support.