This reverts commit 9065f9c5ff073d376eb6377ca63ead93623fc8a3, reversing
changes made to f0b446e55506b251e85afd4bb063586bccb52eb2.

Upgrade gemojione to 3.0.0

Upgrades gemojione to 3.0.0, see the Changelog: https://github.com/jonathanwiesel/gemojione/blob/b98aa8b07eef815d4d3f52ff3c8714b28932b0de/CHANGELOG.md#v300-2016-07-12

[Here are all the new 2016 emoji](http://emojione.com/releases/2.2.4/) :tada:

This update has new emoji and more sensical categories.

See merge request !5237

Content Security Policy

Ref: #18231 

This uses twitter's [secure_headers gem](https://github.com/twitter/secureheaders).

See merge request !4770

This adds the 2016 emoji as well as support for using SVG images instead of PNGs.

It also fixes a number of incorrectly categorized emoji and other minor issues.

Upgrade Rake task for Gemojione 3.0.0 and generate sprites.

Upgrade aliases.json by pulling down index.json from the gemojione repository and running the generate_aliases.rb file.

Changelog: https://github.com/jonathanwiesel/gemojione/blob/master/CHANGELOG.md#v301-2016-07-16

For the specific emoji added to the Unicode standard, see: http://emojione.com/releases/2.2.4/

Huge kudos to Jonathan Wiesel (@jonathanwiesel) for his work on the gemojione gem!

Upgrade to Rouge 2.0

## What does this MR do?

This MR is a refactor of the HTMLGitlab formatter. The original was copy-pasted from the legacy HTML formatter and adapted to suit our needs. In particular, this MR:

* Strips dead code and unused options
* Factors out the "wrapping" into the places that care about it - Bonzai and the view helpers
* Uses the Rouge 2.0 `token_lines` method to split tokens into lines, removing the custom code we used to do the same
* Uses the now-public `span` method instead of re-implementing it ourselves
* Removes options to not split into lines - the places where this feature wasn't being used are now using the plain `Formatters::HTML` instead of this class

See merge request !4691

Update rubocop to 0.41.2

Adds a couple of cops to the TODO files, but I wanted [a specific cop](https://github.com/bbatsov/rubocop/pull/3135/files) which just had about 65 offences, so Ill do that later.

See merge request !4999