Modify trace api

@mortenvp I finished the unit tests and fixed the todos as good as i could. Please let me know what you think? :)
It is a pragmatic choice. This code is not triggered unless somebody puts kodo::enable_trace on one of stacks using this helper.. So instead of having to modify the helper every time we need to track down a bug.. you can just enable tracing on the stack and it will start to print out stuff.