Deactivate the sallogareas plugin

It's boring and a waste of time to have to keep registering in
include/sal/log-areas.dox new log areas that other people have introduced.

We don't really have a uniform policy for logging anyway, so why bother trying
to enforce a such for the log areas? Anybody uses whatever log areas and log
output style and formatting they want in the code they happen to be working
on. And that's fine with me. We were supposed to be the project that avoids
unnecessary process, rules and bureaucracy, right?

Change-Id: I6bddcb56b58edcd885e5dc743c8730878de0036d