Merge branch 'hotfix/3.1.4'
Fix the file permissions of the ACE editor
Correctly export pages as PDF (see #6317)
Fix the versions diff viewer
Correctly handle the autologin key if a member is duplicated (see #5945)
Add `width:100%` to `.long` (see #6320)
Correctly sort by date in the listing module (see #5609)
Allow FAQ categories without a redirect page (see #6226)
Correctly mark corrupt extensions in the extension manager
Do not show file paths and line numbers in the extension manager

The information is written to the logs already and is not valuable for non-admin users
Also update the sitemap if a news/event feed is updated (see #5727)
Merge branch 'hotfix/3.1.5' into develop

Conflicts:
	system/docs/CHANGELOG.md
Handle tables without keys in `Database::listFields()` (see #6310)
Initialize `$arrReturn` in `Database\Result::fetchAllAssoc()` (see #6328)
Make `Frontend::getMetaData()` public static (see #6325)
Add the "isVisibleElement" hook (see #6311)
Correctly display nested wrapper elements (see #5976)