Tool functional tests - allow disambiguation of params in conditionals.

Disambiguate by add prefix for parent (or any number of direct ancestors) with pipe (|). See included test case for an example.

Should fix twill and API driven functional tests.
Twill-less tool tests - handle composite inputs.

Add example tool test for composite data (worked with Twill based test framework prior to this commit, works with API based framework as a result of this commit).