Description:
------------
It seems that ResourceBundles will never get destroyed. This is favorable for performance reasons, as the resource files do not need to be reloaded at each request.
However, when developing a page it is very annoying. The lock handle that ResourceBundle puts on the resource file (on Windows) requires you to restart your webserver whenever you want to rebuild your language files.
It would be nice to have a forth parameter $persistent in the constructor of ResourceBundle which can trigger this behavior.

Bug #53969 says this was just the way ICU worked; however, a function ures_close is given by ICU. uresbund.cpp says in entryCloseInt:
  Entries are left in the cache. TODO: add ures_flushCache() to force a flush of the cache.
If this makes it impossible to provide disabled persistency, this bug should be left open until the TODO is done within ICU.

Test script:
---------------
<?php
   class rb extends ResourceBundle {
      public function __destruct() {
         echo 'I will never come up.';
      }
   }
   $rb = new rb('en_US', 'path/to/res/files', true);
?>