Use slash as path separator

[idle-code]

Currently whole project uses dot '.' as path separator. Perhaps it would be easier for users (at least PC-based) to switch to UNIX slash instead.
In general separator should be configurable option.

[idle-code]

Mixed approach could be used where only action names use dot as a separator and slash is used elsewhere.

[idle-code]

Perhaps Path (from pathlib) could be used instead of NodePath.