perl client and flush_all

Hello:

As near as I can tell, Cache::Memcached does not have a flush_all
method.  Find attached a patch that adds support for it.

If there is a version of the perl client that already supports it, I'd
appreciate the pointer.

Best,
-- 
Patrick Michael Kane
<modus@xxxxxxxx>

memcached_flushall.patch
Description: Text document