closes #7622

closes #7617

- Removed posts and non contacts from other's data
- Collections are exported in batches to lower memory footprint
- In base exporters create User object instead of keeping instance because it caches all associations

closes #7627

It is not included into the main test suite, because it has :performance tag.

One can run this test using command:
$ bin/rspec --tag performance spec/integration/export/memory_usage_spec.rb

This test creates additional fixtures set to speed up repeated runs.

Main purpose of fixtures for us is to speed up test runs. Rebuilding
fixtures each run makes them pointless. They will be rebuilt automatically
if some of "files_to_check" are changed, so we're protected from the case
when fixtures are outdated and don't load properly.

It was possible to run migration locally without providing old private
key. This way migration was performed but not dispatched, which obviously
leads to desynchronization of the federation state so let's validate sender
before performing any actual actions.

closes #7558

closes #7614

closes #7594

closes #7583

closes #7600

closes #7599

Use the already available contacts data for the prefill

Fixes #7586

Use the already available data about the recipient for the prefill

closes #7590

Follow-up for #7578

Fixes #7587

The locals option is only supported in ActionView::TestCase, so it is
ignored anyway (even worse, it disabled the complete assertion). I added
some more assertions to ensure the template is rendered with the correct
conversation.

closes #7588

This was added by accident with the rails5 upgrade

closes #7550

And cleanup old reshares with deleted root posts

closes #7578

This was in all stack traces, which confused people ...

We currently only support IE11, so the version check was already old
again ...

When we break old browser versions, we don't check that for other
browsers. So older IE browser just break, like very other older browser
too.

closes #7557

closes #7571

closes #7530

closes #7546

closes #7545

closes #7544

closes #7542

Fixes #7541

This commit introduces support for AccountMigration federation message
receive. It covers the cases when the new home pod for a user is remote
respective to the recepient pod of the message. It also allows to initiate
migration locally by a podmin from the rails console. This will give the
pods a possibility to understand the account migration event on the
federation level and thus future version which will implement migration
will be backward compatible with the pods starting from this commit.

Add explicit mutual contact creation to the DataGenerator#generic_user_data
which is used in account deletion tests.