[REVIEW] Feature/403 move memcache config parsing

fixes #403 

SSP has as complicated memcache config including multiple server groups containing multiple servers. initially a memcache connection ws provided by the di container. Since the di container has to be phased out in favor of Symfony DI. The memcache connection itself is not (yet) used but can be used by Doctrine. So only the config parsing has been moved to a bundle.