Okay I promised this a few days ago and never followed up. Here's how to get that annoying HTTP traffic logging out of your main log (or if you are using axiomatic start -n, off of your terminal):
exarkun@boson:~/Scratch/Run/demo$ axiomatic -d my.axiom/ web --http-log httpd.log
That's all. If the server was running while you did this, you will have to restart for it to take effect ;) Of course, someone could contribute a patch to change that...
One other thing: this command, unlike the others I've shared, depends on current trunk and will not work in a released version of Mantissa. There's probably a Mantissa release coming up pretty soon, though.