hdf5_ep

[svn-r7669] Purpose:
    Refactor code

Description:
    Use "template macro" technique to eliminate a huge amount of repeated code
in type initialization code (almost 1000 lines, between this change and the
changes to the H5Tconv.c file earlier).
    This centralizes the common parts of the code and makes the different parts
of the code more obvious.

Platforms tested:
    FreeBSD 4.9 (sleipnir)
    too minor to require h5committest