RFC: APCIterator class

Here is a rough patch of what I have currently in my working copy for  
an APCIterator class.  Check out the tests for some examples but it  
looks something like:

<?php
$it = new APCIterator('user', $regex, $chunk_size);
foreach($it as $key=>$value) {
   echo $key."\n";
}
?>

Some code probably needs to be cleaned up and I need to add a delete 
() method along with the ability to only dump entry values rather  
than the full entry info (which it does by default currently).  
Locking names also conflict with sma.c which I'll need to resolve.

The primary purpose here is to allow iterating large caches in  
$chunk_size steps, grabbing $chunk_size entries per lock instance so  
it free's the cache locks for other activity rather than holding up  
the entire cache to grab the first 100 entries or the first 100  
entries matching a regex.  Regex is also moved into the C level so  
it's faster than grabbing all the entries and iterating over them in  
PHP arrays as is currently required.

-shire

http://tekrat.com/patches/apc_iterator.patch