[TASK] Made abstract ExceptionHandler class an interface.

- Updated documentation to reflect new changes.

src/Pecee/Handler/ExceptionHandler.php

@@ -1,11 +0,0 @@
-<?php
-namespace Pecee\Handler;
-
-use Pecee\Http\Request;
-use Pecee\SimpleRouter\RouterEntry;
-
-abstract class ExceptionHandler {
-
-	abstract public function handleError(Request $request, RouterEntry $router = null, \Exception $error);
-
-}

src/Pecee/Handler/IExceptionHandler.php

@@ -0,0 +1,11 @@
+<?php
+namespace Pecee\Handler;
+
+use Pecee\Http\Request;
+use Pecee\SimpleRouter\RouterEntry;
+
+interface IExceptionHandler {
+
+	public function handleError(Request $request, RouterEntry $router = null, \Exception $error);
+
+}

src/Pecee/SimpleRouter/RouterBase.php

@@ -2,7 +2,7 @@
 namespace Pecee\SimpleRouter;
 
 use Pecee\Exception\RouterException;
-use Pecee\Handler\ExceptionHandler;
+use Pecee\Handler\IExceptionHandler;
 use Pecee\Http\Middleware\BaseCsrfVerifier;
 use Pecee\Http\Request;
 
@@ -187,8 +187,8 @@ class RouterBase {
     protected function handleException(\Exception $e) {
         if($this->request->loadedRoute !== null && $this->request->loadedRoute->exceptionHandler !== null) {
             $handler = new $this->request->loadedRoute->exceptionHandler();
-            if(!($handler instanceof ExceptionHandler)) {
-                throw new RouterException('Exception handler must be instanceof ExceptionHandler.');
+            if(!($handler instanceof IExceptionHandler)) {
+                throw new RouterException('Exception handler must be instanceof IExceptionHandler.');
             }
 
             $handler->handleError($this->request, $this->request->loadedRoute, $e);