Refactor the web app bootstrapping code

- All custom JS variables are now preloaded into the `app.data` object, rather than directly on the `app` object. This means that admin settings are available in `app.data.settings` rather than `app.settings`, etc.
- Cleaner route handler generation
- Renamed ConfigureClientView to ConfigureWebApp, though the former still exists and is deprecated
- Partial fix for #881 (strips ?nojs=1 from URL if possible, so that refreshing will attempt to load JS version again)

src/Asset/AssetManager.php

@@ -1,117 +0,0 @@
-<?php
-/*
- * This file is part of Flarum.
- *
- * (c) Toby Zerner <toby.zerner@gmail.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Flarum\Asset;
-
-use DomainException;
-
-class AssetManager
-{
-    /**
-     * @var CompilerInterface
-     */
-    protected $less;
-
-    /**
-     * @var CompilerInterface
-     */
-    protected $js;
-
-    /**
-     * @param CompilerInterface $js
-     * @param CompilerInterface $less
-     */
-    public function __construct(CompilerInterface $js, CompilerInterface $less)
-    {
-        $this->js = $js;
-        $this->less = $less;
-    }
-
-    /**
-     * @param $filename
-     */
-    public function setFilename($filename)
-    {
-        $this->js->setFilename($filename.'.js');
-        $this->less->setFilename($filename.'.css');
-    }
-
-    /**
-     * @param string $file
-     */
-    public function addFile($file)
-    {
-        $ext = pathinfo($file, PATHINFO_EXTENSION);
-
-        switch ($ext) {
-            case 'js':
-                $this->js->addFile($file);
-                break;
-
-            case 'css':
-            case 'less':
-                $this->less->addFile($file);
-                break;
-
-            default:
-                throw new DomainException('Unsupported asset type: '.$ext);
-        }
-    }
-
-    /**
-     * @param string[] $files
-     */
-    public function addFiles(array $files)
-    {
-        array_walk($files, [$this, 'addFile']);
-    }
-
-    /**
-     * @param callable $callback
-     */
-    public function addLess(callable $callback)
-    {
-        $this->less->addString($callback);
-    }
-
-    /**
-     * @param callable $callback
-     */
-    public function addJs(callable $callback)
-    {
-        $this->js->addString($callback);
-    }
-
-    /**
-     * @return string
-     */
-    public function getCssFile()
-    {
-        return $this->less->getFile();
-    }
-
-    /**
-     * @return string
-     */
-    public function getJsFile()
-    {
-        return $this->js->getFile();
-    }
-
-    public function flushCss()
-    {
-        $this->less->flush();
-    }
-
-    public function flushJs()
-    {
-        $this->js->flush();
-    }
-}