Enables to generate pictures thumbnails in an AJAX way.

This plugin is similar to the 'thumbnail' menu in piwigo admin part, and performs the same actions as it. It differs from native piwigo feature in the fact that ALL thumbnails are generated, without having to re-submit the generation form, and without being dependent on php timeout restrictions.

This plugin is suitable when there are bunches of thumbnails to generate, as an alternative to offline thumbnail generation.

However, please keep in mind that this approach, when having a lot of thumbnails to generate, is not advised when using mutualized infrastructures, since it is a CPU-greedy approach that may go against provider SLA.