Site fixes

Fixes dart-lang/www.dartlang.org#1112
Here I just meant to remove the `{{baseUri}}`. But after I did this the Polymer transformer complained that `_href` must only be used with a variable inside and that `href` must be used instead if the value is static (it seems that `_href` is meant to generate a `href`...).

I haven't tried on Dartium as far as I can remember (only tried dart2js on Chrome) and I couldn't find a case where this was needed :) But basically the issue we had on `www.dartlang.org` seemed to be that `../` was used for `{{baseUri}}`making the page refresh recursively in its iframe.