+ generate docs.
+ added nesista and Darni to the acks.
+ __call__() must return the outcome.
* sys.argv is handled by hand.
- do not run the test itself, let the caller handle that.
+ a little more of doc.
+ RunningCommandWrapper hadles catching the exception sh raises on command failure, return code is saved in an attribute and commands can be casted to bool to see if the command succeeded or not.
+ explain how RunninCommandWrapper changes command failure behavior.