Change name of bash completion file to just "cowsay"
    
    Change the name of the installed bash completion file from
    "cowsay.bashcomp" to "cowsay".
    
    Of the 1000+ files in /usr/share/bash-completion/completions/ on my
    system, no other file is called "*.bashcomp". Most are just called
    the same as their respective command.
    
    We also let the filesystem package take care of owning the
    directory /usr/share/bash-completion/ and its subdirectories.