[JP] - Merged changes from various branches and Added Traversor
Merge remote-tracking branch 'origin/instantiate_from_json' into instantiate_from_json

Conflicts:
	restnavigator/exc.py
	restnavigator/halnav.py
	restnavigator/j.py
	restnavigator/traverser.py
	tests/test_hal_nav.py
Merge remote-tracking branch 'origin/instantiate_from_json' into instantiate_from_json
Fixing issues with NIR clones, restricted fetch to idempotent navigator