Dialog should clip content overflow

[amcclain]

This might be more general than just the Exception dialog - we should review and ensure a fix is applied at the most efficient level. In general I think think we would ever want a dialog to overflow like this.

XH.handleException('This is an error with a reallyLongStringLikeTheKindOfThingThatCanBeProducedByExceptionsAndStuffLikeThatWeHaveSeen and it overflows')