vchoi_fork

[svn-r4329] Purpose:
    Bug Fix
Description:
    The datatype conversion buffer size was only halfway converted from hsize_t
    to size_t and was causing problems.  Also, the H5P_peek_<foo> routines have
    a bunch of identical code.
Solution:
    Finished converting the datatype conversion buffer size to size_t and
    cleaned up the implementation of the H5P_peek_<foo> routines to call a
    common routine instead of reimplementing a bunch of code.
Platforms tested:
    Solaris 2.7 (arabica)