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

[Daniel Kegel]

Donohue, Michael wrote:
> Last, the localhost lock file now includes part of the host name.  We 
> have 4 “localhosts” in use here on shared disks.  Without this change, 
> they all used the same lockfiles.  This meant that box 2 would not do 
> any linking, because box 1 was already doing 4.  ...  
> 
> One outstanding problem is that with multiple “localhosts” using 1 shared 
> directory, orphan detection doesn’t work so well.  We’ve just turned it 
> off, but that results in many orphans.   

standard distcc practice is to *not* use network shared directories
for the lockfiles.   Can you test putting the lockfiles on a local
disk and see if that improves performance over your current results?

Putting the hostname on distcc's housekeeping files is probably a good
idea even so, since some people will insist on using shared directories
(presumably so distccmon shows them more info?)
and we do want that to perform as well as it can even if it's
not the recommended mode.