exports.util object is a hack to expose internal calls made by instructions, so
that externally created intructions can benefit from them. This is made
necessary by the absence of a clear framework for writing external instructions.
Calls exposed:
	exports.util.updateTransactionState
	exports.util.updateTransactionStatus
	exports.util.pushTransactionError
bugfix: enqueuedAt field not transfered from writer transaction
to resulting transaction.