created via remote look-up when domains differ but point to the same resource

This makes the UI appear less laggy. After all, the status *is* created
right there and then, it's the distribution to home timelines that can take
a while

a11y: Improve icon button component regarding semantics, screen reader usage

a11y: Add labels to input fields for screenreader

Add touch icons for Chrome, iOS and Windows 10

See: https://dequeuniversity.com/rules/axe/2.1/label

footprint of each running process by 128mb

add permissive CORS to API controllers

a11y: Add HTML lang attribute and utf8 encoding meta tag

See: https://dequeuniversity.com/rules/axe/2.1/html-has-lang

all statuses/accounts to assemble, but at least lists don't have to be
re-rendered all the time now. Also add "mention" dropdown option

to the API

Add specs for Button, DisplayName, DropdownMenu components