Issue 11362 - Unit test assertion failure messages not printed

Issue URL: http://d.puremagic.com/issues/show_bug.cgi?id=11362
Regression commit from pull #636: db7dc40ad4a8e9ea9827224d8d4d799ef24810ca
Merge pull request #648 from denis-sh/fix-issue-11362

Issue 11362 - Unit test assertion failure messages not printed