[CORE][EVENTS] Bring existing Events and Boostrapper back

- Adapt the existing event system to rely on Symfony's event dispatcher

src/Util/Common.php

@@ -0,0 +1,48 @@
+<?php
+// This file is part of GNU social - https://www.gnu.org/software/social
+//
+// GNU social is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GNU social is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace App\Util;
+
+class Common
+{
+    public static function normalizePath(string $path): string
+    {
+        if (DIRECTORY_SEPARATOR !== '/') {
+            $path = strtr($path, DIRECTORY_SEPARATOR, '/');
+        }
+        return $path;
+    }
+
+    public static function pluginFromPath(string $path): ?string
+    {
+        $plug = strpos($path, '/plugins/');
+        if ($plug === false) {
+            return null;
+        } else {
+            $cut = $plug + strlen('/plugins/');
+            $cut2 = strpos($path, '/', $cut);
+            if ($cut2) {
+                $final = substr($path, $cut, $cut2 - $cut);
+            } else {
+                // We might be running directly from the plugins dir?
+                // If so, there's no place to store locale info.
+                Log::error("The GNU social install dir seems to contain a piece named plugin");
+                return false;
+            }
+        }
+        return $final;
+    }
+}