transaction outputs are not validated when applying a block

[wanderingbort]

This is related to #174 but ends up being more broadly applicable in view of partial validating nodes.

Fully-validating/producing nodes will not depend on the output member of a Processed(Generated)Transaction however, partial validating nodes do.

As such, part of accepting a block should be verifying that the output generated by local application exactly matches the output encoded in the block. This includes the notify, sync and async outputs.