This refactors the code used for checking if a user has exceeded the
personal projects limit. As part of this refactor the method has been
renamed from Project#check_limit to "check_personal_projects_limit", as
this name makes it much more clear what the purpose of the method is.
Standalone unit tests have also been added, as before we only had a
single generic validation test that did not cover all cases.

The old implementation of the refactored method also included a `rescue`
statement. This code would only run when a project creator was not set.
The error that would be added wasn't super useful, especially since
there would already be errors for the creator not being present. As none
of the other code in the "check_personal_projects_limit" raises, it has
been removed.

Refactor only/except configuration policies

See merge request gitlab-org/gitlab-ce!24359

Fix failing MySQL spec due to deadlock condition

Closes #55161

See merge request gitlab-org/gitlab-ce!24378

Ignore Repository::AmbiguousRefError in db/fixtures/development

See merge request gitlab-org/gitlab-ce!24366

Introduce `default:` configuration entry setting that makes it possible
to configure a default value of an entry, what overrides class-level
`def self.default` value.

Backporting a change in ee branch

See merge request gitlab-org/gitlab-ce!23559

Resolve "When merging an MR, the squash checkbox isn't always supported"

Closes #52278

See merge request gitlab-org/gitlab-ce!24296

Remove cancel all jobs button in general jobs list view

Closes #34665

See merge request gitlab-org/gitlab-ce!24010

Make parseBoolean idempotent

See merge request gitlab-org/gitlab-ce!24365

`spec/features/uploads/user_uploads_file_to_note_spec.rb` was failing in
master because MySQL detected a deadlock when a DELETE and INSERT for
the same indexed item occurred within a transaction in the `uploads`
table.  Due to InnoDB's next-key locking algorithm
(innodb_locks_unsafe_for_binlog in
https://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.html), InnoDB
sets an exclusive lock for any of the indexed records it encounters, so
the INSERT will fail until the DELETE is committed.

To fix this, we just disable the transaction for MySQL and keep
it for PostgreSQL.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/55161

Clarify cluster integration link is for all Kubernetes

See merge request gitlab-org/gitlab-ce!24364

Generate searchable JSDoc documentation

See merge request gitlab-org/gitlab-ce!23583

Externalize strings from `/app/views/projects/project_members`

See merge request gitlab-org/gitlab-ce!23227

Remove all `$theme-gray-{weight}` variables in favor of `$gray-{weight}`

Closes #56266

See merge request gitlab-org/gitlab-ce!24333

Moves shared code into a mixin

See merge request gitlab-org/gitlab-ce!24322

Add Import/Export dev docs

Closes #36055

See merge request gitlab-org/gitlab-ce!23835

Signed-off-by: Rémy Coutable <remy@rymai.me>

GitLab 11.4.3 "Outbound requests" setting path

See merge request gitlab-org/gitlab-ce!22898

Not just GKE

Fix no avatar not showing in user selection box

Closes #56268

See merge request gitlab-org/gitlab-ce!24346

Add 11.7 -> 11.8 update doc

See merge request gitlab-org/gitlab-ce!24283

Resolve "Add "What's new" menu item in top navigation"

Closes #25341

See merge request gitlab-org/gitlab-ce!23186

Fix Bitbucket Server importer error handling

Closes #56154

See merge request gitlab-org/gitlab-ce!24343

Ensure pool participants are linked before GC

Closes gitaly#1354

See merge request gitlab-org/gitlab-ce!24230

Bump minimal node version from 6 to 8.10.0

Closes #54065

See merge request gitlab-org/gitlab-ce!24305

Update Gitaly documentation to indicate which version shipped with Gitaly TLS support

See merge request gitlab-org/gitlab-ce!24334

In theory the case could happen that the initial linking of the pool
fails and so do all the retries that Sidekiq performs. This could lead
to data loss.

To prevent that case, linking is done before Gits GC too. This makes
sure that case doesn't happen.

Adjust applied suggestion reverting previous changes

Closes #56017

See merge request gitlab-org/gitlab-ce!24250