vchoi_fork

[svn-r12603] Description:
    Add a bunch more regression tests:
        - Verify opening a fractal heap more than once works correctly
        - Check that 0 & 1-sized object insertions are handled correctly
        - Check that bad heap IDs are detected when attempting to read an
            object
        - Check that doubling tables with different parameter values are
            working correctly

    Add some more checks to the code to detect 0-sized object insertions and
bad heap IDs for reading.

Tested On:
    FreeBSD/32 4.11 (sleipnir)
    Linux/32 2.4 (heping)
    Linux/64 2.4 (mir)
    Solaris/64 2.9 (shanti)