Massive refactor

- Use contextual namespaces within Flarum\Core
- Clean up and docblock everything
- Refactor Activity/Notification blueprint stuff
- Refactor Formatter stuff
- Refactor Search stuff
- Upgrade to JSON-API 1.0
- Removed “addedPosts” and “removedPosts” relationships from discussion
API. This was used for adding/removing event posts after renaming a
discussion etc. Instead we should make an additional request to get all
new posts

Todo:
- Fix Extenders and extensions
- Get rid of repository interfaces
- Fix other bugs I’ve inevitably introduced

src/Extend/Formatter.php

@@ -1,24 +0,0 @@
-<?php namespace Flarum\Extend;
-
-use Illuminate\Contracts\Container\Container;
-
-class Formatter implements ExtenderInterface
-{
-    protected $name;
-
-    protected $class;
-
-    protected $priority;
-
-    public function __construct($name, $class, $priority = 0)
-    {
-        $this->name = $name;
-        $this->class = $class;
-        $this->priority = $priority;
-    }
-
-    public function extend(Container $container)
-    {
-        $container->make('flarum.formatter')->add($this->name, $this->class, $this->priority);
-    }
-}