vchoi_fork

[svn-r2694] Purpose:
    Bug fix
Description:
    H5Sget_simple_extent_npoints return type is hsize_t and the error value is
    0, but it is possible to have 0 points in a dataset with an unlimited
    dimension, but no data written yet.
Solution:
    Changed H5Sget_simple_extent_npoints return type to hssize_t and the error
    value to -1
Platforms tested:
    FreeBSD 4.1.1 (hawkwind)