Merge branch '3.0'

diff --cc wcfsetup/install/files/lib/system/api/composer.json
index bdf84f200f5f078edf8c00bc9a48f0ee0398a5d2,8c51c2676e8aa3df5d4778ee7c91457862fc317d..8b94087cb353b3919b0afeebed4b6f41ce8e66c6
--- 1/wcfsetup/install/files/lib/system/api/composer.json
--- 2/wcfsetup/install/files/lib/system/api/composer.json
+++ b/wcfsetup/install/files/lib/system/api/composer.json
@@@ -4,11 -4,9 +4,11 @@@
          "prepend-autoloader": false
      },
      "require": {
-         "ezyang/htmlpurifier": "4.9.*",
+         "ezyang/htmlpurifier": "4.12.*",
          "erusev/parsedown": "1.7.*",
          "pelago/emogrifier": "1.2.*",
 +        "chrisjean/php-ico": "1.0.*",
 +        "true/punycode": "~2.0",
          "pear/net_idna2": "^0.2.0"
      }
  }

diff --cc wcfsetup/install/files/lib/system/api/composer.lock
Simple merge

diff --cc wcfsetup/install/files/lib/system/api/composer/installed.json
Simple merge