hdf5doc

Description:
    ADGuide/Changes.html
        Copy file from 1.10 branch.
        Create initial "Changes in 1.10.0" section.
        Remove 1.8.16 section.
    ADGuide/Changes_1_8_x.html
        Add file from 1.10 branch.
        Add 1.8.16.
    ADGuide/Changes_1_4-1_6.html
        Add file from 1.10 branch.
Tested:  Firefox