Allow site creation as 'guest'

[audiodude]

Many potential users have expressed that they do not wish to login using Google, or that they might not even have a Google login available.

Currently, login is only used to associate site data (Sites/Releases/Tracks) with a user, in order for it to be persistent across browsers/devices.

It is completely possible that we could allow a user to create and edit a site as a "guest", where they are warned that all of their data is tied to their browser session and will be lost if they are in an Incognito window or clear their cookies (or use another device). In this case, we just generate a random User ID and put it in a cookie, and associate all data with that.