URL generation doesn't allow for proxied CouchDB under a prefix

[gdamjan]

My CouchDB database is proxied behind nginx under a prefix /db/. Here's the nginx config for completness:
location /db/ {
rewrite /db/(.*) /$1 break;
proxy_pass http://127.0.0.1:5984/;
}

Focus breaks hard in this configuration. Some examples are:

• focus.js: $.getJSON("/_session/", ...
• index.html: <script src="/_utils/script/jquery.js">
  etc..

One sollution would be to always use relative urls.