Eliminated PoolableObjectFactory, KeyedPoolableObjectFactory and replaced them with PooledObjectFactory, KeyedPooledObjectFactory, the (formerly) subclasses that create and operate on PooledObjects.  Similarly replaced the base factories with PooledObject versions.  Modified SoftReferenceObjectPool to manage PooledObjects.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/pool/trunk@1512140 13f79535-47bb-0310-9956-ffa450edef68