vchoi_fork

[svn-r12823] Description:
    Add support for compress heap blocks in "managed" heaps.

    Also, fix bug when the first direct block moves between having a parent
and not having one (and vice versa), which occurs when the heap moves between
having a direct root block and having an indirect root block.

Tested on:
    FreeBSD 4.11 (sleipnir) w/threadsafe
    Linux/32 2.4 (heping) w/C++ & FORTRAN
    Linux/64 2.4 (mir) w/build-all & 1.6 compat