the current syntax doesn't work properly in Rails 5, the resulting query
looks like:
HAVING "events"."project_id" IN (0)

instead of:
HAVING "events"."project_id" IN (SELECT "projects"."id" FROM...

Also we should not use ActiveRecord internal methods. In this case we
can filter projects in WHERE clause instead of doing this in HAVING
clause. Usage of WHERE should be also more efficient because grouping
is then done on much smaller subset of records.

`.exists` should not be used because it's an internal ActiveRecord
method, but we can easily generate the same sql query with `EXISTS`.

Use cattr_accessor directly inside the defined class, otherwise
in Rails 5 this accessor returns nil.

# Conflicts:
#	app/controllers/projects/clusters/gcp_controller.rb
#	app/views/projects/clusters/gcp/_form.html.haml
#	app/views/projects/clusters/gcp/login.html.haml

Improve structure of snippets documentation

See merge request gitlab-org/gitlab-ce!19234

Add Wiki and Snippets to project feature overview

See merge request gitlab-org/gitlab-ce!19235

[ci skip]

Update "col-xs" usage to bootstrap4

Closes #47002

See merge request gitlab-org/gitlab-ce!19256

Make Repository#blob_data_at a public method

See merge request gitlab-org/gitlab-ce!19259

Add missing usage_ping_enabled to API settings

See merge request gitlab-org/gitlab-ce!19263

Fix   after sign-in with Google button

Closes #45551

See merge request gitlab-org/gitlab-ce!19249

Identified while resolving conflicts in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/5906

Upgrade eslint 3 -> 4

Closes #40476

See merge request gitlab-org/gitlab-ce!19182

Line profiling modal width

Closes #46999

See merge request gitlab-org/gitlab-ce!19253

This reduces conflicts with EE, where it is public because it is
called in ee/lib/gitlab/ci/external/file/local.rb.

Resolve "BS4: Import project page is missing margins and wells"

Closes #46879

See merge request gitlab-org/gitlab-ce!19215

Remove version lock on awesome_print dependency

See merge request gitlab-org/gitlab-ce!19232

Only preload member records for the relevant projects/groups/user in projects API

See merge request gitlab-org/gitlab-ce!18945

Replace grape-route-helpers with our own grape-path-helpers

Closes #45718

See merge request gitlab-org/gitlab-ce!19240

Simplify spec: `2.times.each` -> `2.times`

See merge request gitlab-org/gitlab-ce!19242