added exception handling changes to changelog.

changelog.md

@@ -5,4 +5,5 @@
 - Moved **system/db/manager.php** to **system/db.php**. Updated alias appropriately.
 - Unspecified optional parameters will be removed from URLs generated using route names.
 - Fixed bug in Config::set that prevented it from digging deep into arrays.
-- Replace Crypt class with Crypter class. Ditched static methods for better architecture.
+- Replace Crypt class with Crypter class. Ditched static methods for better architecture.
+- Re-wrote exception handling classes for better architecture and design.