#3124762: Add 'lifecycle' key to .info.yml files Added the ability for modules and themes to convey information about their lifecycle via a lifecycle and lifecycle_link key in their info.yml file.
The module listing page now uses this information to show a warning icon and either Deprecated or Obsolete next to the module name if it is one of those statuses. This links to the lifecycle link for the module (a page on Drupal.org with more information).

The modules confirm page now has title 'Are you sure you want to install experimental/deprecated/experimental and deprecated modules?' (depending on what modules are being installed) and lists both experimental and deprecated modules if you attempt to enable modules of either type.
