A Memcache (libmemcached) cache adapter implementation. Requires
[pecl/memcached](http://pecl.php.net/package/memcached).				
The `Memcache` cache adapter is meant to be used through the `Cache` interface,
which abstracts away key generation, adapter instantiation and filter
implementation.

A simple configuration of this adapter can be accomplished in `config/bootstrap/cache.php`
as follows:

{{{
Cache::config(array(
    'cache-config-name' => array(
        'adapter' => 'Memcached',
        'host' => '127.0.0.1:11211'
    )
));
}}}

The `'host'` key accepts entries in multiple formats, depending on the number of Memcache servers
you are connecting to. See the `__construct()` method for more information.

This Memcache adapter provides basic support for `write`, `read`, `delete`
and `clear` cache functionality, as well as allowing the first four
methods to be filtered as per the Lithium filtering system.

This adapter supports multi-key `write` and `read` operations.