Breaking: #111108 - GFX setting thumbnails removed 

See forge#111108

Description 

The setting $GLOBALS['TYPO3_CONF_VARS']['GFX']['thumbnails'] has been removed. It is removed from config/system/settings.php on upgrade.

The setting turned off thumbnails of images in the page module, in the file references of records, in the file list, the file browser and the link browser. The rest of the backend, for example the clipboard, the metadata of files, the live search and the workspaces module, showed thumbnails regardless of it.

The backend now shows thumbnails of images everywhere. Whether the file list, the file browser and the link browser show them is still chosen by every user. In the file list, options.file_list.enableDisplayThumbnails in user TSconfig still controls that choice.

Impact 

Installations that had turned thumbnails off show thumbnails of images in the page module, in the file references of records and, where users choose so, in the file list, the file browser and the link browser.

Affected installations 

Installations whose config/system/settings.php sets $GLOBALS['TYPO3_CONF_VARS']['GFX']['thumbnails'] to false, and extensions that read the setting. The extension scanner reports them.

Migration 

None for installations, the upgrade removes the setting. Extensions that read it drop that condition.