Prevent transient Capybara timeouts during feature tests

The problem occurred because asset compilation takes a long time, so
when the asset cache didn't exist and the first test ran, it would often
(randomly) time out during the generation before the actual test even
had a chance to run.

Now we check if the cache exists before the suite runs, and if not, we
manually fire a request to the root URL in order to generate it. This
should allow subsequent tests to use the cached assets.

See merge request !2646

Revert "Revert "Remove the `:coffee` and `:coffeescript` Haml filters""

This reverts commit b0145d76.

See merge request !2642

fix syntax error on 2.1 and rubocop on 2.2

Background:

Hashes `{:'key': 'value'}` are not valid in 2.1 but are recommended by Rubocop on 2.2. We only use those when we have a key such as `weird-key`, `weird.key`, etc... 

We could disable Rubocop but it wouldn't warn us about the recommended syntax since `Ruby 1.9`: `{key: 'value'}`, which is valid for `Ruby 1.9+`.

Workaround 1 could be disabling `Style/HashSyntax:` in `rubocop.yml`. 

Workaround 2 (tried in this MR) is to trick Rubocop using `.to_sym` which is effectively the same as adding the `:`. This would allow to keep the warning in place.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/12801

See merge request !2637

The problem occurred because asset compilation takes a long time, so
when the asset cache didn't exist and the first test ran, it would often
(randomly) time out during the generation before the actual test even
had a chance to run.

Now we check if the cache exists before the suite runs, and if not, we
manually fire a request to the root URL in order to generate it. This
should allow subsequent tests to use the cached assets.

Correctly determine MR diff base when MR has merge conflicts

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/12779

See merge request !2632

Fix highlighting in blame view.

See merge request !2630

This reverts commit b0145d76.

Backport LDAP user assignment changes from EE

See https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/146

See merge request !2641

Update sentry-raven gem.

Should resolve `fatal: Not a git repository (or any of the parent directories): .git` warnings.

Fixes #12657

See merge request !2636

See https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/146

Show list of forks for a given Project

Closes #2406

See merge request !2376

Save list sort in a cookie

Closes #5546 

See merge request !2537

Fix preventing migration from crashing in very specific cases

Closes #12606. Closes #12501.

/cc @yorickpeterse @dbalexandre 

See merge request !2600

Improve consistency and duplication for Merge Request API

* Follow REST for merge request API route
* Remove repeating comments API for MR
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Fixes #4759 and #11810 

See merge request !2639

Removed sorted text from dropdowns

![Screen_Shot_2016-01-28_at_09.04.36](/uploads/9e0e1fdb45ad12d122f860a2164d9396/Screen_Shot_2016-01-28_at_09.04.36.png)

Closes #12796 

cc @creamzy @jschatz1 

See merge request !2635

* Follow REST for merge request API route
* Remove repeating comments API for MR
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Makes ol margin big enough for 3 digits.

Fixes #7960 

![Screen_Shot_2016-01-25_at_11.20.03_PM](/uploads/73c4b9e939fe108fb3b8221e16e686bd/Screen_Shot_2016-01-25_at_11.20.03_PM.png)


See merge request !2608

Adds feature: Ajax Close/Open updates discussion automatically

Triggers jQuery event <br/>
Fixes #5544

See merge request !2610

This ensures that rake tasks that don't need a DB connection can be run
without one.

Return a fake application settings OpenStruct when this is not the case.
Also, use ActiveRecord::Base.connection_pool.active_connection? instead
of ActiveRecord::Base.connection.active? to avoid driver exception.

Closes #12796

[ci skip]

[ci skip]

Update Ruby version to 2.2.4 (latest previous stable) and update docs

Tests and issues added to https://github.com/gitlabhq/gitlabhq/issues/8696 were all fine after the upgrade. 

Main issue: https://gitlab.com/gitlab-org/gitlab-ce/issues/3340

See merge request !2534

Improve performance of retrieving last update times for events

See 75195eefcca4cb3961986c90c8e837da02f30134 and
https://gitlab.com/gitlab-org/gitlab-ce/issues/12415#note_3387317
for the juicy details.

Related issue: https://gitlab.com/gitlab-org/gitlab-ce/issues/12415

See merge request !2613

Skip the 2FA requirement during logout

See merge request !2581