hdf5doc

Description:
    Specs.html
        Add "HDF5 Specifications" collection.  Initial contents:
            HDF5 File Format Specification
            DDL in BNF for HDF5 
            HDF5 Image and Palette Specification
            HDF5 Dimension Scale Specification
            HDF5 Table Specification
    Specifications/
        Add subdirectory for specifications documents that 
        are not already included elsewhere in the document set.  
        Existing documents are not being moved at this time.
Tested:  Firefox