vchoi_fork

[svn-r7482] Purpose:
    Bug fix

Description:
    The MPI_File_set_size() routine on ASCI Red is not able to extend files
so that they are larger than 2GB.

Solution:
    Add an extra macro which controls whether MPI_File_set_size() can handle
>2GB offsets or if our "older" way of reading a byte, then writing a byte at
the appropriate offset should be used.

Platforms tested:
    FreeBSD 4.9 (sleipnir)
    h5committest