fixes #7997

closes #7998

Closes #7972

closes #7976

closes #7959

fixes #7942

closes #7943

closes #7926

fixes #7808

closes #7913

fixes #7840

closes #7884

closes #7890

closes #7882
fixes #7841

closes #7924

closes #7905

fixes #7838

closes #7909

closes #7868

Facebook removed the API and facebook integration is broken now, so lets
remove it.

closes #7874

Fixes #7852

closes #7853

Fixes #7854

closes #7839

closes #7833

Previous file history in 80dfdcd6, couldn't keep it.

LinksController redirects requests for provided diaspora:// links to
respective entities urls.

This is required to make url_for(StatusMessage.new) work

fixes #7770

closes #7774

closes #7814

When public fetch is requested with Poll guid, return parent
StatusMessage for it, which includes the Poll in its turn.

closes #7815

I missed it in #7803

closes #7807

Use completed_at datetime field as an indication of a performed migration

closes #7805

Adds support for merging accounts with account migration by eliminating
duplicate data in favor of the target user's data.

closes #7803

closes #7791

closes #7778

closes #7772

Some podmins were confuse how they can disable this redirect and I think
the rule with two users can actually be a little confusing. I think the
main goal of this page to give the podmin a little start and I think
after they configured everything, the pod works and they found the link
to the wiki to make themself an admin, it is OK to remove the redirect.

Also it's bad for single-user pods where this page always stays active,
even if they are an admin, but have only one user. It's more useful for
single-user pods to have the login on the home page.

closes #7783

Fixes #6564.

closes #7775

closes #7769