hdf5_ep

[svn-r5964] Purpose:
    Internal feature.

Description:
    To complement the "get the class's path" functionality, there needs to be
    a way to open a generic property class with a path.

Solution:
    Implement the "open a class by path" functionality.  Also, add internal
    testing routines.

Platforms tested:
    FreeBSD 4.6 (sleipnir) (too small for triple testing)