warning mentions preview into area where actual content would be

overshadow requirement for remote-lookup

work flawlessly was a nightmare). WARNING: This commit makes the web UI connect to the streaming API instead
of ActionCable like before. This means that if you are upgrading, you should set that up beforehand.

sounds complex, but really it just reorganizes the posting options and
adds a seperator line

redis-backed "mentions" timeline as redundant (given notifications)

nested inside a common parent (<Account>), instead they all embed <HeaderContainer />

the public timeline has been using

Currently we have the problem where the follow request button is missing
from the Follow request tab. This means that when you visit that tab you
either have to press the back button in the browser or re-enter the home
page, which breaks the app flow.

This will resolve that issue by adding a new back button to that tab,
in the same way that the public timeline, and favourites have.

for extremely wide monitors

Federate spoiler_text using warning attribute on <content /> instead of a <category term="spoiler" />
Clean up schema file from accidental development migrations

Also, since the root component connects to the stream that updates home/notification columns,
there is pretty much no case for refreshing those columns beyond initial load. So, move the
loading of those columns into the root component, to prevent unneccessary reloads when switching tabs
on mobile or resizing desktop window between mobile/desktop layouts

application website validation, don't link to app website if website isn't set,
also comment out animated boost icon from #464 until it's consistent with non-animated version