Signed-off-by: GretaD <gretadoci@gmail.com>

Do not combine threads with identical subjects

Build message threads after each sync and store thread root ID for later reference

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

Merge pull request #3361 from nextcloud/dependabot/composer/symfony/event-dispatcher-contracts-1.1.9

Bumps symfony/event-dispatcher-contracts from 1.1.7 to 1.1.9.

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps symfony/service-contracts from 1.1.8 to 1.1.9.

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [phpspec/prophecy](https://github.com/phpspec/prophecy) from 1.10.3 to 1.11.1.
- [Release notes](https://github.com/phpspec/prophecy/releases)
- [Changelog](https://github.com/phpspec/prophecy/blob/master/CHANGES.md)
- [Commits](https://github.com/phpspec/prophecy/compare/v1.10.3...1.11.1

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

Add real-world test for a linear message thread

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

Implement the jwz threading algorithm

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

Make sure all commands return an int

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

Store the `references`, `in-reply-to` and the thread root id

Bumps [vimeo/psalm](https://github.com/vimeo/psalm) from 3.12.1 to 3.12.2.
- [Release notes](https://github.com/vimeo/psalm/releases)
- [Commits](https://github.com/vimeo/psalm/compare/3.12.1...3.12.2

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [ezyang/htmlpurifier](https://github.com/ezyang/htmlpurifier) from 4.12.0 to 4.13.0.
- [Release notes](https://github.com/ezyang/htmlpurifier/releases)
- [Changelog](https://github.com/ezyang/htmlpurifier/blob/master/NEWS)
- [Commits](https://github.com/ezyang/htmlpurifier/compare/v4.12.0...v4.13.0

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [phan/phan](https://github.com/phan/phan) from 3.0.3 to 3.0.5.
- [Release notes](https://github.com/phan/phan/releases)
- [Changelog](https://github.com/phan/phan/blob/master/NEWS.md)
- [Commits](https://github.com/phan/phan/compare/3.0.3...3.0.5

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [nikic/php-parser](https://github.com/nikic/PHP-Parser) from 4.5.0 to 4.6.0.
- [Release notes](https://github.com/nikic/PHP-Parser/releases)
- [Changelog](https://github.com/nikic/PHP-Parser/blob/master/CHANGELOG.md)
- [Commits](https://github.com/nikic/PHP-Parser/compare/v4.5.0...v4.6.0

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [friendsofphp/php-cs-fixer](https://github.com/FriendsOfPHP/PHP-CS-Fixer) from 2.16.3 to 2.16.4.
- [Release notes](https://github.com/FriendsOfPHP/PHP-CS-Fixer/releases)
- [Changelog](https://github.com/FriendsOfPHP/PHP-CS-Fixer/blob/2.16/CHANGELOG.md)
- [Commits](https://github.com/FriendsOfPHP/PHP-CS-Fixer/compare/v2.16.3...v2.16.4

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [phpdocumentor/type-resolver](https://github.com/phpDocumentor/TypeResolver) from 1.2.0 to 1.3.0.
- [Release notes](https://github.com/phpDocumentor/TypeResolver/releases)
- [Commits](https://github.com/phpDocumentor/TypeResolver/compare/1.2.0...1.3.0

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [myclabs/deep-copy](https://github.com/myclabs/DeepCopy) from 1.9.5 to 1.10.1.
- [Release notes](https://github.com/myclabs/DeepCopy/releases)
- [Commits](https://github.com/myclabs/DeepCopy/compare/1.9.5...1.10.1

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>