tests: avoid spurious TAP errors on Mac OS X 10.7

tests: avoid spurious TAP errors on Mac OS X 10.7

Fixes automake bug#1897.  Reported by Max Horn.

* t/suffix8.tap: The libtool bug#11895 was causing the ./configure script
to output a stray "ok" string on a line of its own, confusing the TAP
driver into thinking this was an extra test result (which resulted in the
next, real test results being flagged as "OUT-OF-ORDER").  Fix this by
protecting configure output.
* t/suffix10.tap: Likewise, and for the "make distcheck" output as well.
* THANKS: Update.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>