[DomainBPlusTree] New Feature: Created a new subclass of the
DomainBPlusTree that uses JVSTM's PerTxBoxes to implement an
optimization to calculate the size() of a tree, which is now O(1)
[Consistency Predicates] Minor Change: Used the new optimized
DomainBPlusTreeJVSTM in the relation between the DomainMetaClass and the
existing DomainMetaObjects