Vertically centered featured-section text

The parent's display style is set to table and its height is defined.
The text is wrapped in a div and its display is set to table-cell and
vertical-align is set to middle.
Added circular background to the robot image

Since the background is a part of the image itself, the background and
the robot scale together easily without having to define the circle's
width and height and using absolute positioning. This also removes the
need for border-radius, which is not supported in IE 7.

One disadvantage is that the color, shape, and size of the background is
not easily modifiable, as the image itself must be edited. Additional
featured items would also require the same embedded background.
Removed vcenter class

Since only the featured text needs to be vertically centered, the rules
may be applied using its ID selector
Improved readability and comments of style sheets
Added correct navbar links