Revert "Remove Zend/Locale from our vendor library"

This reverts commit 9b2bff4d17189089eb8a9513f70421a068b4d540.

At least Zend/Filter/Alnum.php requires Zend_Locale.
Remove Zend/Locale/Data/*.xml

This should be safe.
Throw exception on E_NOTICE

Use of uninitialized values must be detected asap.