vchoi_fork

[svn-r12776] The internal change is to make the 3 parameters of H5Pset_fapl_direct be a structure and passed
through driver info functions in H5FD_direct_open, H5FD_direct_read, and H5FD_direct_write.  The
external change is to add a new API function H5Pget_fapl_direct to query 3 control values, the
memory boundary, file system block size, and the maximal buffer size for copying data.