MessageHandlerModule - a functonal way of declaring message handler pipelines.
Remove IMessageHandler, IMessageResolver and update all areas to use HandlerModule
Fix namespace
DispatchSingle - fail if single handler not found
massive reorg
Move types in Projections namespace to Handlers. Rename ProjectionHost to DurableCommitDispatcher
prepping for printable specifications
Merge branch 'master' into cedar-testing
example code on how to use the Scenario DSL