Add corresponding unit test.

Further testing needed.

Update dependent code accordingly.

code cleanup

Use OpmResult defined in error module.

Fix clippy warnings.

Remove example trait_test.
Doc fixes.

Separate Dottable trait to additional file.

Various doc work

This simply forwards incoming LightResult.
Rename RefNode::new -> RefNode::from_node to fix clippy warnings.

Function was completely rewritten. Fixed many clippy warnings and
reformatted code.

Add splitting ratio to Beamsplitter (not used yet).

Add example src-detector.