Add a link to the file's history in the file's blame page
    
    Similarly to the previous commit where we added a link to the file's
    history page from the page where you can see the content of a file.
    We're adding here a link to the file's history page from the "blame"
    page for the file.
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>