[distcc] Limiting cpp0, randomizing hosts, more verbose localhost lockfile names

[logic at jrlogic.dyndns.org]

> Our local setup is that no compiling is done locally.  We've got big
> enough jobs that the local machine is busy with linking and
> preprocessing.  We also found that going above about -j 15 didn't
> improve total time to compile by much, even on a 4 processor box.
>
>
>
> Limiting the preprocessor helps achieve a healthy level of parallelism.
> Currently, we have to carefully adjust the parallel factor in make, so
> that it doesn't overwhelm the local machine.  By using lock files to
> control that instead, we can now dramatically increase the j factor, and
> it doesn't slow down the build.
> Michael

Try using:
$ make -j -l8
on a 4 processor box. This instructs job control to restrict the load to 8
(loosely approximated to 8 jobs wanting to be in a running state
simultaneously). If all of the compilation is done remotely, several
preprocessor tasks can run, hopefully with most blocking on network I/O
allowing full use of system CPU resources with active preprocessing.