Allow default transitions to be provided by the stack.
Allow default transitions to be provided by the stack.

joansmith/tripleplay,tomfisher/tripleplay,tomfisher/tripleplay,tomfisher/tripleplay,tomfisher/tripleplay,joansmith/tripleplay,joansmith/tripleplay,joansmith/tripleplay,joansmith/tripleplay,tomfisher/tripleplay