Added a test to check that exceptions in callbacks are not consumed by the event stream handler.
Added a test to check that exceptions in callbacks are not consumed by the event stream handler.

RafaelPalomar/girder,opadron/girder,jcfr/girder,kotfic/girder,essamjoubori/girder,Xarthisius/girder,jcfr/girder,chrismattmann/girder,opadron/girder,chrismattmann/girder,Kitware/girder,msmolens/girder,essamjoubori/girder,data-exp-lab/girder,Xarthisius/girder,manthey/girder,RafaelPalomar/girder,RafaelPalomar/girder,msmolens/girder,msmolens/girder,jbeezley/girder,girder/girder,sutartmelson/girder,manthey/girder,salamb/girder,essamjoubori/girder,Xarthisius/girder,Xarthisius/girder,data-exp-lab/girder,salamb/girder,kotfic/girder,adsorensen/girder,RafaelPalomar/girder,data-exp-lab/girder,sutartmelson/girder,Kitware/girder,jcfr/girder,jbeezley/girder,chrismattmann/girder,adsorensen/girder,jbeezley/girder,adsorensen/girder,Kitware/girder,girder/girder,kotfic/girder,sutartmelson/girder,jcfr/girder,chrismattmann/girder,kotfic/girder,kotfic/girder,data-exp-lab/girder,sutartmelson/girder,data-exp-lab/girder,Kitware/girder,opadron/girder,manthey/girder,jbeezley/girder,girder/girder,Xarthisius/girder,salamb/girder,essamjoubori/girder,adsorensen/girder,sutartmelson/girder,adsorensen/girder,jcfr/girder,opadron/girder,RafaelPalomar/girder,opadron/girder,salamb/girder,essamjoubori/girder,girder/girder,msmolens/girder,msmolens/girder,chrismattmann/girder,salamb/girder,manthey/girder