Add memetastic.space to instance list

It's uh, it's an instance now.

Add https://icosahedron.website/

Activity stream background should use $color5

in case of debugging incoming salmons. Add <thr:in-reply-to /> to favourite
salmons because it seems to be required by GS.

Remove toot.zone

toot.zone is being discontinued

StreamEntry model. Simply render Salmon slaps as they are needed

I haven't had a chance to test this, because I don't currently have a fully functioning computer I can set up a dev-environment on, but this *should* make it so when a user toggles a post to be private, a disclaimer appears clarifying what "private" really means.

Add variable for text of privacy disclaimer

Allow PuSH to distribute private toots with that condition

if account lock info was up to date, otherwise re-do the FollowService
with now updated information

Add gnusocial.me to instance list