[MERGE] TestBed scripting

Any objections to adding the updated build-test scripts to bzr?

The current round have been broken out into a master test script and a
set of control files for configured builds specific to certain OS
environments (for testing packages builds)
with a layered design for independently testing components build.
This last layered control files still have to be determined, but that
can be done incrementally.

The entire set is loosely modeled along the same lines as some binary
packaging environments. But geared towards full compile testing instead
of package generation.

I've broken off the shell script prefixes to make it somewhat portable
and added a top-level test-builds.sh for manually kicking the process
off in one easy step.

Amos

-- 
Please use Squid 2.7.STABLE3 or 3.0.STABLE7