Exception: Use Hoa\Exception.

The core is being splitted into several libraries. `Hoa\Exception` is
one of them.

Author: Hywan

Exception.php

@@ -36,16 +36,16 @@
 
 namespace Hoa\Stringbuffer;
 
-use Hoa\Core;
+use Hoa\Exception as HoaException;
 
 /**
  * Class \Hoa\Stringbuffer\Exception.
  *
- * Extending the \Hoa\Core\Exception class.
+ * Extending the \Hoa\Exception\Exception class.
  *
  * @copyright  Copyright © 2007-2015 Hoa community
  * @license    New BSD License
  */
-class Exception extends Core\Exception
+class Exception extends HoaException
 {
 }

composer.json

@@ -21,8 +21,9 @@
         "source": "http://git.hoa-project.net/"
     },
     "require": {
-        "hoa/core"  : "~2.0",
-        "hoa/stream": "~0.0"
+        "hoa/core"     : "~2.0",
+        "hoa/exception": "~0.0",
+        "hoa/stream"   : "~0.0"
     },
     "autoload": {
         "psr-4": {