[FEATURE] Support for custom csrf verifier

- Added support for custom csrf verifier.
- Updated documentation.

src/Pecee/Http/Middleware/BaseCsrfVerifier.php

@@ -11,9 +11,39 @@ class BaseCsrfVerifier extends Middleware {
     const POST_KEY = 'csrf-token';
     const HEADER_KEY = 'X-CSRF-TOKEN';
 
+    protected $except;
+
+    /**
+     * Check if the url matches the urls in the except property
+     * @param Request $request
+     * @return bool
+     */
+    protected function skip(Request $request) {
+
+        if($this->except === null || !is_array($this->except)) {
+            return false;
+        }
+
+        foreach($this->except as $url) {
+            $url = rtrim($url, '/');
+            if($url[strlen($url)-1] === '*') {
+                $url = rtrim($url, '*');
+                $skip = (stripos($request->getUri(), $url) === 0);
+            } else {
+                $skip = ($url === rtrim($request->getUri(), '/'));
+            }
+
+            if($skip) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     public function handle(Request $request) {
 
-        if($request->getMethod() != 'get') {
+        if($request->getMethod() != 'get' && !$this->skip($request)) {
 
             $token = (isset($_POST[self::POST_KEY])) ? $_POST[self::POST_KEY] : null;