[tlbuild] trial builds for TL'13

[Karl Berry]

Hi Thomas,

Glad we got past the timestamp madness.

    exit status is a bit bizarre.
    ...
    # FAIL:  1

The exit status is nonzero because a test failed.  Which one?
(Look back in the log.)

I suspect/hope it will be dvitomp.test, which failed for Dick too.
(And for me, with some compiler versions but not others.)

Thanks,
karl