PUBDEV-1483: Grid testing.  Added stacktrace printing to aid debugging.  Information in exception is not enough.
PUBDEV-1483: Grid testing.  Added stacktrace printing to aid debugging.  Information in exception is not enough.

h2oai/h2o-3,michalkurka/h2o-3,mathemage/h2o-3,jangorecki/h2o-3,h2oai/h2o-dev,h2oai/h2o-3,h2oai/h2o-3,jangorecki/h2o-3,mathemage/h2o-3,h2oai/h2o-dev,spennihana/h2o-3,h2oai/h2o-dev,spennihana/h2o-3,mathemage/h2o-3,h2oai/h2o-3,spennihana/h2o-3,h2oai/h2o-3,mathemage/h2o-3,jangorecki/h2o-3,jangorecki/h2o-3,mathemage/h2o-3,h2oai/h2o-dev,jangorecki/h2o-3,mathemage/h2o-3,spennihana/h2o-3,spennihana/h2o-3,michalkurka/h2o-3,h2oai/h2o-dev,h2oai/h2o-dev,michalkurka/h2o-3,michalkurka/h2o-3,michalkurka/h2o-3,jangorecki/h2o-3,jangorecki/h2o-3,mathemage/h2o-3,h2oai/h2o-3,michalkurka/h2o-3,spennihana/h2o-3,h2oai/h2o-3,spennihana/h2o-3,h2oai/h2o-3,h2oai/h2o-dev,michalkurka/h2o-3