login page auto-focus on username field

As described in ticket: https://issues.apache.org/jira/browse/COUCHDB-2373

Small thing, but it was bugging me. :)
no worries, we are mostly not that picky, I just noticed that you changed them back, and sometimes I changed them the other way round :D 

So my thought was let's avoid all this work and stick to one version in the future :) 

I would merge that if it is okay for you, I am +1 - just wanted to talk and discuss about that.