added a new acceptance test for issue 1277
Fixed the acceptance test for Saga issue 1277
Nested data class in saga
added another unit test for 1277 to make sure that reply messages to
saga's get correlated properly without requiring an explicit context mapping
Looking up sagas using all finders, fixes #1277

Unfortunately this fix has the side effect of undoing the performance improvement done in https://github.com/NServiceBus/NServiceBus/commit/85031041d21aea3f92f2db93525a8b3472d0a950
Need to figure out a better way.