Upgrade to L5 + huge refactor + more. closes #2

New stuff:
- Signup + email confirmation.
- Updated authentication strategy with remember cookies. closes #5
- New search system with some example gambits! This is cool - check out
the source. Fulltext drivers will be implemented as decorators
overriding the EloquentPostRepository’s findByContent method.
- Lay down the foundation for bootstrapping the Ember app.
- Update Web layer’s asset manager to properly publish CSS/JS files.
- Console commands to run installation migrations and seeds.

Refactoring:
- New structure: move models, repositories, commands, and events into
their own namespaces, rather than grouping by entity.
- All events are classes.
- Use L5 middleware and command bus implementations.
- Clearer use of repositories and the Active Record pattern.
Repositories are used only for retrieval of ActiveRecord objects, and
then save/delete operations are called directly on those ActiveRecords.
This way, we don’t over-abstract at the cost of Eloquent magic, but
testing is still easy.
- Refactor of Web layer so that it uses the Actions routing
architecture.
- “Actor” concept instead of depending on Laravel’s Auth.
- General cleanup!

src/Core/Exceptions/InvalidConfirmationTokenException.php

@@ -0,0 +1,7 @@
+<?php namespace Flarum\Core\Exceptions;
+
+use Exception;
+
+class InvalidConfirmationTokenException extends Exception
+{
+}

src/Core/Exceptions/PermissionDeniedException.php

@@ -0,0 +1,7 @@
+<?php namespace Flarum\Core\Exceptions;
+
+use Exception;
+
+class PermissionDeniedException extends Exception
+{
+}

src/Core/Exceptions/ValidationFailureException.php

@@ -0,0 +1,40 @@
+<?php namespace Flarum\Core\Exceptions;
+
+use Illuminate\Support\MessageBag;
+
+class ValidationFailureException extends \InvalidArgumentException
+{
+    protected $errors;
+
+    protected $input = array();
+
+    public function __construct($message = '', $code = 0, Exception $previous = null)
+    {
+        parent::__construct($message, $code, $previous);
+        $this->errors = new MessageBag;
+    }
+
+    public function setErrors(MessageBag $errors)
+    {
+        $this->errors = $errors;
+
+        return $this;
+    }
+
+    public function getErrors()
+    {
+        return $this->errors;
+    }
+
+    public function setInput(array $input)
+    {
+        $this->input = $input;
+
+        return $this;
+    }
+
+    public function getInput()
+    {
+        return $this->input;
+    }
+}