Update styles to allow for sign-up link to be an arbitrary size (bug 834615)

This change allows for longer strings in the sign-up link.

It switches to using floats for the logged-out view. The text-indent changes were necessary to prevent webkit eating part of the link when width of the link is 'auto'.

Lastly this also impacted the suggested search content. To make that both work for logged in/out the suggestions are aligned with nav in both cases. To make that possible the suggestions container was moved inside the nav element.