Description:
    - Fixed a few comments that Doxygen gave warnings on.
    - Removed stylesheet from configuration so Doxygen will use the default
        stylesheet and removed the CLANG-related lines to eliminate another
        error since we're not using that feature, so the lines should not
        present. (from cpp_doc_config)
Platforms tested:
    Linux/32 2.6 (jam) - only changing comments



git-svn-id: https://svn.hdfgroup.uiuc.edu/hdf5/trunk@25020 dab4d1a6-ed17-0410-a064-d1ae371a2980