Unused Modules

Over time your website gets unwieldy so it needs cleaning up. Though it's simple to find what modules are enabled/disabled, it's rather difficult to find out if this is true for a project.

This is a helper / development module that lists unused modules / projects that can be safely deleted. This makes your repository cleaner and your website faster.

Naming / nomenclature
* Project: a project that has its own namespace and can be downloaded from Drupal.org. Say "Views".
* Module: a project can contain multiple modules. Say "views" and "views_ui".

Examples
* Module "views_ui" is disabled and module "views" is enabled. The project "views" is not safe to delete.
* Module "admin_menu" is disabled and module "admin_menu_toolbar" is also disabled. The project "admin_menu" is safe to delete.

Notes / caveats
* Core modules are not listed, never delete them!
* If a module occurs multiple times it is listed only once and always in the most specific location. This is because the method to track modules is a Drupal function that returns modules that can be enabled. That function favours specific (/sites/your-site) over generic (/sites/all). See https://www.drupal.org/node/176046 .
* Always make a full backup of your database and codebase before deleting modules!
* Always uninstall modules before deleting them.
* Double / triple check results!!!

Usage
* Drupal admin ui: /admin/config/development/unused_modules
* Drush: $ drush unused-modules
* (Drupal 7 only) Site-audit: $ drush audit-extensions

See README for detailed instructions.

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