Basic support for cache store

including minimum support for memcached using net.spy:spymemcached:2.11.4

Signed-off-by: Robin Smith <robin.smith@clicktravel.com>
Memcached is the standard java tool kit for connecting to memcache nodes of which elasticache is

There is a aws fork of this tool kit however it is only available as a downloaded jar file and not via any public repositories and as such cannot be used within cheddar.