OFBIZ-4098 Extract interfaces for CacheManager and Cache, add basic abstract and concrete factories and move the current cache implementation into a separate package. 



git-svn-id: https://svn.apache.org/repos/asf/ofbiz/branches/OFBIZ-4098-make-cache-pluggable@1647934 13f79535-47bb-0310-9956-ffa450edef68