hdf5

[svn-r12517] Description:
    Fix the last scattered bunch of problems with the object deletion code,
which appears to be completely working now (for objects that are stored
within heap blocks - standalone objects aren't implemented yet).

    Also, re-work the regression test to speed up some of the existing tests
and add in 100-200 more combinations of tests - overall, its probably even
slower than it was... :-/

Tested:
    FreeBSD 4.11 (sleipnir)
    Linux 2.4 (chicago)
    Mac OS X (amazon)