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)
Correctly mark corrupt extensions in the extension manager
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