Improving autocomplete performance part 2

Related issue: gitlab-org/gitlab-ce#3507

See merge request !2253

Bump bootstrap-sass to ~> 3.3.0

Resolves bootlint error:

`bootlint:  W013  Bootstrap version might be outdated. Latest version is at least 3.3.6 ; saw what appears to be usage of Bootstrap 3.3.5`

See merge request !2275

Bump cal-heatmap-rails to ~> 3.5.0



See merge request !2276

Expire view caches when application settings change

If the admin disables Gravatar, for example, before the views would not invalidate. Now they invalidate automatically when this happens.

Closes #5728

See merge request !2280

docs: raketasks: Add documentation on uploading to mounted shares

Fog has a local storage provider, which can be use to copy backups to locally mounted cifs / nfs / smb shares. This MR adds documentation to doc/raketasks/backup_restore.md in response to #3387.

@stanhu I found some time tonight and was able to get this started earlier than I initially expected, glad I could contribute.

See merge request !2246

Update copyright notice to 2016 [ci skip]

Don't attempt to set Referrer policy in Safari

While Safari supports the policy, it does not (currently, as of 9.x)
recognize `origin-when-cross-origin` as a valid value, so we omit the
policy entirely under Safari.

Closes #5609

See merge request !2269

Closes #5728

Some were no longer needed, others needed `!important`.

The old way broke d3, for some reason.

Fix typo in CI settings

Remove a little typo in the CI section of the settings.

See merge request !2270

Fix broken SVN migration link

Closes https://gitlab.com/gitlab-com/doc-gitlab-com/issues/45

See merge request !2271

[ci skip]

While Safari supports the policy, it does not (currently, as of 9.x)
recognize `origin-when-cross-origin` as a valid value, so we omit the
policy entirely under Safari.

Closes #5609

[ci skip]

Spinach fix

/cc @rspeicher @rdavila 

See merge request !2263

Nokogiri produces inefficient XPath expressions when given CSS
expressions such as "a.gfm". Luckily these expressions can be optimized
quite easily while still achieving the same results.

In the two cases where this optimization is applied the run time has
been reduced from around 170 ms to around 15 ms.

Around 300 ms (in total) would be spent in these delegated methods due
to the extra stuff ActiveSupport adds to the compiled methods. Because
these delegations are so simple we can just manually define the methods,
saving around 275 milliseconds.

This is a tad faster than letting Nokogiri figure out whether it should
evaluate the query as CSS or XPath and then actually evaluating it.

See merge request !2262

See merge request !2252

While it's useful to keep track of the different versions (Ruby, GitLab,
etc) doing so for every point wastes disk space and possibly also RAM
(which InfluxDB is all to eager to gobble up). If we want to see the
performance differences between different GitLab versions simply looking
at the performance since the last release date should suffice.

Swap Author and Assignee Selectors on issuable index view

Closes #4039

See merge request !2256

[ci skip]

Why did this break? `¯\_(ツ)_/¯`

Closes #4039

Remove unused config/schedule.rb file

[ci skip]

See merge request !2249

[ci skip]

Ensure that is no pending migrations when using database on
Gitlab::CurrentSettings

This fixes the undefined method `recaptcha_enabled' for
#<ApplicationSetting:0x007f28552f8238> when running the build.

See merge request !2254

Added additional config environmental variables to help Debian packaging

* GITLAB_EMAIL_FROM
* GITLAB_EMAIL_DISPLAY_NAME
* GITLAB_EMAIL_REPLY_TO

This is a followup on https://gitlab.com/gitlab-org/gitlab-ce/issues/3717

See merge request !2251