Add the proper Exception message for all JSON error types by PHP (#110)

Author: gbalduzzi

src/JWT.php

@@ -352,8 +352,10 @@ private static function handleJsonError($errno)
     {
         $messages = array(
             JSON_ERROR_DEPTH => 'Maximum stack depth exceeded',
+            JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON',
             JSON_ERROR_CTRL_CHAR => 'Unexpected control character found',
-            JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON'
+            JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON',
+            JSON_ERROR_UTF8 => 'Malformed UTF-8 characters' //PHP >= 5.3.3
         );
         throw new DomainException(
             isset($messages[$errno])