hdf5doc

Description:
    In h5dump:  
        Added -z, -q, -m options.
        Removed "not yet implemented" tag from -B.
            -- Closes Bugzilla 1126 in the 1.8 branch.
        Rewrote -p option description; added compression ratio information.
        Added long option names, where they were missing.
        Updated "History" section.
    Added ph5diff (within h5diff description).
    In h5diff:  
        Added new command-line syntax.  
            (Old syntax remains in file but is commented out as it 
            will not be available in 1.8.1 version of h5diff.)
        Added -V option.
        Expanded description of optional "object" parameters.
        Added long option names, where they were missing.
        Updated "History" section.
    In h5repack:  
        Added -V, -L, -c, -d, -s options.
            -- Closes Bugzilla 1136 in the 1.8 branch.
        Added N-bit and scale/offset filters to -f description.
        Added long names for all options.
        Reinstated old command-line syntax alongside new syntax 
            and -i and -o in "Options and Parameters."
        Added "History" section.
    Significant copy edits and formatting.
Tested: Firefox