Application bootstrap refactor

- Extract environment properties in Environment class
- Replaces initialisation closure by ApplicationLoader class
- Removes undesirable error handling/PHP settings modifications

lib/Alchemy/Phrasea/Core/Middleware/SetupMiddlewareProvider.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Alchemy\Phrasea\Core\Middleware;
+
+use Assert\Assertion;
+use Silex\Application;
+use Silex\ServiceProviderInterface;
+use Symfony\Component\HttpFoundation\Request;
+
+class SetupMiddlewareProvider implements ServiceProviderInterface
+{
+    /**
+     * Registers services on the given app.
+     *
+     * This method should only be used to configure services and parameters.
+     * It should not get services.
+     * @param Application $app
+     */
+    public function register(Application $app)
+    {
+        Assertion::isInstanceOf($app, \Alchemy\Phrasea\Application::class);
+
+        $app['setup.validate-config'] = $app->share($app->protect(function (Request $request) use ($app) {
+            if (0 === strpos($request->getPathInfo(), '/setup')) {
+                if (!$app['phraseanet.configuration-tester']->isInstalled()) {
+                    if (!$app['phraseanet.configuration-tester']->isBlank()) {
+                        if ('setup_upgrade_instructions' !== $app['request']->attributes->get('_route')) {
+                            return $app->redirectPath('setup_upgrade_instructions');
+                        }
+                    }
+                } elseif (!$app['phraseanet.configuration-tester']->isBlank()) {
+                    return $app->redirectPath('homepage');
+                }
+            } else {
+                if (false === strpos($request->getPathInfo(), '/include/minify')) {
+                    $app['firewall']->requireSetup();
+                }
+            }
+        }));
+    }
+
+    /**
+     * Bootstraps the application.
+     *
+     * This method is called after all services are registered
+     * and should be used for "dynamic" configuration (whenever
+     * a service must be requested).
+     */
+    public function boot(Application $app)
+    {
+        // no-op
+    }
+}