Thread-safe Catch

Catch test framework is nice, but not thread-safe - see https://github.com/philsquared/Catch/issues/99

There is thread-safe fork of Catch https://github.com/ned14/Catch-ThreadSafe
At the time of writing this original Catch is 1.2.1 whilst thread-safe fork 1.1

With or without you (exceptions)

To exception, or not to exception, that is the question.
What about cyclomatic complexity argument? E.g. http://programmers.stackexchange.com/questions/219872