vchoi_fork

[svn-r2001] Purpose:
    Bug fix.
Description:
    Failed on T3E in which int32 is typedef to a short (4 bytes)
    but the converter just used H5T_NATIVE_INT for conversion of
    a STD_INT32.  Int in a T3E is actually 64bit big.
Solution:
    Recoded the h5type to h4type matching algorithm by making sure
    the size of the H4 type used is equal to the size of the
    H5 native type.
    Remark: current implementation is not efficient--it does all
    the sizes checking repeatedly.  Should have done the type mapping
    once at the beginning as initialization.
    Old code are still retain via the macro NEWWAY.  Need to verify
    the correctness of the converter in more platforms before
    finalized on the code.
Platforms tested:
    Baldric (Solaris 2.6), arabica (Solaris 2.7)
    T3E