Merged manually from 2.7 branch to 3.x trunk.

Merged manually from 2.7 branch to 3.x trunk.

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  r81149 | florent.xicluna | 2010-05-13 23:40:01 +0200 (jeu. 13 mai 2010) | 2 lignes

  Better test skipping, with message in the log.
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  r81150 | florent.xicluna | 2010-05-13 23:41:05 +0200 (jeu. 13 mai 2010) | 2 lignes

  Improve test feedback to troubleshoot issue #8423 on OS X.
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  r81151 | florent.xicluna | 2010-05-14 01:46:48 +0200 (ven. 14 mai 2010) | 2 lignes

  Revert changeset r81150 which helped diagnose issue #8423 on some OS X buildbot.
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  r82056 | florent.xicluna | 2010-06-17 22:30:56 +0200 (jeu. 17 juin 2010) | 2 lignes

  Add few words about test.test_genericpath.CommonTest
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