Optical::name returns node type as default.

Source: add name parameter.

This forces the usage of the "new" function to submit a name.

Update examples accordingly

Separate Dottable trait to additional file.

Add example for trait testing.

Add unit tests.

The original graph is kept untouched.

This is only a preliminary solution until we have a general reporting.

Copied from EnergyMeter. Needs modifications yet.

Update docs. Update filter_test example.

Update documentation.

Tiny doc fixes.

Add serde_yaml crate and add Serialize to spectrum.