ITCR — Add missing default initialization for valuetypes

In 6.18.2 Constructors, Assignment Operators, and Destructors the default constructor of the OBV classes is mentioned. This lacks a description that it should initialize members, proposal is to add to 6.18.2, OBV part, after the first sentence add:

The default constructor initializes object
reference members to appropriately-typed nil object references, basic datatypes to their default value as listed in
Table 6.2, and enums to their first value. All other members are initialized using their default constructors.

Add missing behavior of the default constructor

As suggested by the submitter the behavior of the default constructor for the OBV classes should be mentioned