hdf5doc

Description:
    RM/H5P/H5Pset_core_write_tracking.htm
        Removed statement that setting 'page_size' to 0 turns off write 
            tracking and strengthen statement that that setting 'page_size' 
            to 0 is an error. 
        Added "History" entry for anticipated change in enforced behavior
            at Release 1.8.14.
        -- Fixes "HDFFV-8884 H5Pset_core_write_tracking RM entry contains 
            seemingly-conflicting statements".
        Clarified required parameter values.
        Format and edits for reference manual consistency.
    RM/H5P/H5Pget_core_write_tracking.htm
        Copy edits for consistency with H5Pset_core_write_tracking entry.
Tested:  Firefox