ISPN-4677 Map/Reduce job fails with the wrong explanation on TimeoutException

Master only. See https://issues.jboss.org/browse/ISPN-4677 for discussion and rationale. 
Also looking at this closer, I don't like the idea that we are just rewrapping the InterrruptedException.  It may be the best thing but normally I like to propagate those to the caller if it is possible to respond in a better fashion.  Maybe that isn't possible here.