Ability to change tracking level from topic summary

[erlend_sh (Erlend Sogge Heggen)]

I’m more in favour of fully utilising the right-hand sidebar…

@codinghorror

(And overriding the scroll bar with a completely custom implementation is something we really want to get to…)

As seen on esoTalk and Flarum.

That would pave the way for ‘Natural breakpoints or “chapters” for long topics’ as well.