hdf5_ep

[svn-r16395] Description:
	Bring r16394 back from trunk:

        Rename H5O_msg_read_real -> H5O_msg_read_oh, to be more consistent with
other routines in library.

        Move H5O_msg_read_oh and H5O_msg_exists_oh from package to private
header file, so other routines in library can use them.

Tested on:
        FreeBSD/32 6.3 (duty)
        Too minor to require h5committest