New listen API

Event subscriptions now take place before *any* boot method is called.
This ensures that all event listeners are registered before things
happen – e.g. locales are registered before the translator is
instantiated in the Tags extension's boot method.

src/Support/ExtensionsServiceProvider.php

@@ -21,5 +21,11 @@ class ExtensionsServiceProvider extends ServiceProvider
                 $providers[$extension] = $this->app->register($providerName);
             }
         }
+
+        $events = $this->app->make('events');
+
+        foreach ($providers as $provider) {
+            $provider->listen($events);
+        }
     }
 }