disable the use of CBN in DefaultPossibleWorld, which is used in PF and
LWSampler. But LWSampler doesnot need CBN information.
remove recording usage for objects in abstractPartialWorld.
solve dirtyVar explosion problem in ParticleFiltering
Merge pull request #324 from BayesianLogic/disable-cbn-in-default-pw

solving PF memory growth issue, disable CBN recording objects in LWSampler and ParticleFilter