[PATCH] fix AS crappy performance

[PATCH] fix AS crappy performance

A while ago some guy complained that his server connections / sec was
way down due to AS. The server would fork a process which would then read
some tiny bit of random data and hang around for a while doing nothing.
This defeated all AS's heuristics, and due to a new process being a good
anticipation candidate by default, his performance went bad.

The fix was just to treat new processes as being unsuitable for
anticipation. Fixed. Unfortunately ls, cat, grep, small programs
starting up, find | xargs, etc only submit a couple of requests, and they
really want anticipation to be on.

This patch keeps a simple goodness value per queue based on how successful
anticipation has been for new processes.