popstate messages from the browser don't have an event.state, and i
don't even know what the overridePopState stuff is trying to do. If
event.state is null, try window.location.hash, or the last part of the
URL path.
pseudo-links are now just links, because i'm lazy and it's easier than
fixing an issue. They now take the form `/?invite=code` and
`/accounts/?user=userid`.
ts/modules.tabs.ts is now a wrapper for ts/modules/pages.ts.
Also, fixed no section appearing when visiting the settings tab.
not the happiest with it, but it works alright. PageManager is
instantiated, you pass is Page{} objects, which have a (code)name, page
title, and url, and a show, hide, and shouldSkip function, each
returning a bool. The first two are self explanatory, the last tells you
if the page is disabled for some reason (like on setup some are disabled
if messages are). You can then call load(<(code)name>), or
prev/next(<name>).
