ugly spew at start of test runs?

[Martin Pool]

I think the subject line is a bit over the top.

I added this - someone had spent some time debugging the wrong problem
because they believed they were running a different version of Bazaar.
 I think making it a bit more obvious is good, and the change was
reviewed here.

It also seemed useful to show the python version - the stdlib is not
so necessary, but emitted by the common code from show_version.

I'm sure you never make that kind of mistake but this is not the first
time someone else has.

Martin