Add copy constructor in MLRUCache because it is directly used as a DataType in map.
Add copy constructor in MLRUCache because it is directly used as a DataType in map.

izenecloud/izenelib,izenecloud/izenelib,pombredanne/izenelib,pombredanne/izenelib,izenecloud/izenelib,pombredanne/izenelib,pombredanne/izenelib,izenecloud/izenelib