Description:
------------
PECL memcache extension - memcache.php throws PHP notices when 
viewing an item in the cache that has expired.

this may seem like a weird scenario but it happens frequently 
if you are working with objects that are only cached for a few 
seconds

Reproduce code:
---------------
To reproduce

1. add an item to the cache that has a quick expiration, for example 10 seconds.  

2. view that object in memcache.php.  

3. wait for the expiration and then refresh the page.


PATCH CODE: (insert at aprox line 851)

if (empty($r['VALUE']))
{
echo "<tr><td class=td-0>",$theserver,"</td><td class=td-0>",$theKey,
"</td><td>[The requested item was not found or has expired]</td>",
 "<td></td>","</tr>";
}
else
{
// echo the line normally
	        

Expected result:
----------------
if an expired item is clicked (or the details page refreshed) 
it should show that the item is expired or missing from the 
cache.

Actual result:
--------------
Notice: Undefined index: VALUE in memcache.php on line 860
Notice: Undefined index: VALUE in memcache.php on line 861
Notice: Undefined index: VALUE in memcache.php on line 862