h5ldump command-line options

[wkliao]

Let's add more command-line options to h5ldump. For example,
-k to print whether the file is a regular HDF5 or a log-based.
Or even a NetCDF class file. This is similar to ncdump -k.
-H to print header only. We can add them gradually.

[wkliao]

We can also use option -k to check the output files from all the test programs
whether they are log-based files.

[wkliao]

-k is implemented in 0c91bf5
-H in 32f6c1e