Add proxy on dev server

[krusynth]

Right now, etherpad and the editor are being served on different ports, so they don't share the session cookie as they should. The fix here is to proxy everything through Apache or Nginx to those services with different sub-subdomains. Here's how my local copy has this setup (Apache):

<VirtualHost *:80>
ProxyPass / http://localhost:8080/ retry=0
ServerName frontend.madison.localhost
</VirtualHost>

<VirtualHost *:80>
ProxyPass /ep/ http://localhost:9001/ retry=0
ProxyPass / http://localhost:1337/
ServerName editor.madison.localhost
</VirtualHost>

<VirtualHost *:80>
ProxyPass / http://localhost:9001/ retry=0
ServerName etherpad.madison.localhost
</VirtualHost>