nodes: should not launch dialog on import.
nodes.explorePath: redesigned.
testnodes: updated tests.
Changes to GO_FXN

Changes to GO_FXN
Merge branch 'dev' into MBird
testnodes: wrote more tricky tests and fixed others.
nodes.explorePath: fixed bugs.
Merge branch 'MBird' of https://github.com/mlichtenstein/IEEErobot into MBird

Conflicts:
	pathfinding/nodes.py
	pathfinding/testnodes.py
	src/ld/go_fxn/go_fxn.ino