Polishing up Flo integration code and improving test coverage

- rewritten graph-to-text to a new algorithm that fits the
  new fan-in/fan-out model much better
- polished text-to-graph
- improved test coverage for text-to-graph and graph-to-text
- removed unnecessary code

polish

ensure proper handling of taps on off canvas streams

Ensure correct property name used to tapped stream name

addressed Glenns comments

be consistent in checking/setting isTapLink

Author: aclement