Merge branch 'hotfix/3.2.15' into support/3.2
Send a 301 redirect to forward to the language root page (see #7420)
Display nested wrapper elements with a nested style
Correctly handle 0 in utf8_convert_encoding() (see #7403)
Correctly handle archives being part of multiple RSS feeds (see #7398)
Remove the tooltip of the delete icon of the meta wizard (see #7270)
Check for interfaces in the class loader
Merge branch 'hotfix/3.2.16' into release/3.4.0

Conflicts:
	assets/contao/js/core.js
	system/docs/CHANGELOG.md
	system/modules/core/classes/Frontend.php
	system/modules/core/widgets/MetaWizard.php
Correctly filter empty elements in String::resolveFlaggedUrl()
Merge branch 'fix/nested-wrapper-elements' of https://github.com/madeyourday/contao-core into release/3.4.0

Conflicts:
	assets/contao/js/core.js
Add an empty option to the image size select menu (see #7436)
Show the correct root icon in the page/file picker (see #7409)
Replace leafo/lessphp with oyejorge/less.php (see 7012)
Add the CSS units `vw`, `vh`, `vmin` and `vmax` (see #7417)
Always apply the IE security fix in the Environment class

Apply the IE security fix to both Environment::get('queryString') and Environment::get('requestUri') and use Environment::get('queryString') instead of $_SERVER['QUERY_STRING'].
Merge pull request #7453 from contao/feature/ie-security-fix
Send the request token when toggling the visibility of an element (see #7406)
Correctly store the model in Dbafs::addResource() (see #7440)
Strip insert tags recursively in the strip_insert_tags() function
Add the encodeRequestString() method to the Environment class