trace the scope as a JSON object

[marten-seemann]

This is a different implementation of #45, that leaves the name of a scope a string. Instead, when tracing, we parse the name and determine the scope.

Closes #45.

[vyzo]

this is better in that it leaves the ontological name unmollested.

We might want to cache the parsed scope class in the scope itself, not sure if it has any perf implications.

[marten-seemann]

We might want to cache the parsed scope class in the scope itself, not sure if it has any perf implications.

That would almost be #45 then...