AM_V_GEN - better docs

[Patrick Rutkowski]

The page here mentions the existence of AM_V_GEN: 
http://www.gnu.org/software/hello/manual/automake/Options.html

But, form the perspective of an automake newbie, it doesn't do much more than 
just mention that it's there.

I don't get from that page how to apply to all my $(CC) build commands, and I 
really want to quiet down this very messy "make" output I now have.

The doc page there doesn't even suggest where to look to learn how to apply it 
to your build.

Very confused,
-Patrick