hdf5doc

Purpose:
    Add new tools:
        h5diff
        h5perf
        h5redeploy
        h5c++
    Corrections to h5import

Description:
    h5diff, h5perf, h5redeploy, h5c++ -- Added these tools.
    h5import -- Corrected the description of the naming convention for
        output datasets.  Other edits based on review comments.
    Copy edits and source code formatting.

Platforms tested:
    IE 5, Safari