Find indirect data members

This pull request fixes the testNamedReference unit test in CondCore/ORA.  The problem was that TypeWithDict::dataMemberByName(name) would find only direct data members of a class.
This function was enhanced to also find indirect data members.
Also, I noticed that the default ctor of MemberWithDict() did not explicitly initialize its data member, a pointer.  So this request also explicitly initializes the pointer.

Please merge as soon as convenient.