Speed up username display in header

Display username as soon as possible, as the first item in the header.

Not sure that's the right way to do it at all, though.

![screen shot 2014-07-28 at 13 27 51](https://cloud.githubusercontent.com/assets/85783/3724274/753db9e8-167c-11e4-9b21-622b3d73274f.PNG)
![screen shot 2014-07-28 at 13 25 22](https://cloud.githubusercontent.com/assets/85783/3724276/7b4ca6f0-167c-11e4-928b-f48bc2de5db7.PNG)

![ ](http://gifs.joelglovier.com/lolwat/wtf.gif)
Could we have something similar to [what we have here](https://github.com/guardian/frontend/blob/master/common/app/views/fragments/commonCssSetup.scala.html#L26)? I understand the reasoning for this, but it does create an extra step if you want to have to change the JS.

Perhaps, however, this JS won't change enough to warrent it.