config: make indiBlacklist optional
screenshot: make F1 the root family for simplicity
config: make edgeVisibleDirected optional
config: make edgeInvisibleRed optional
config: make considerAgeDead optional
config: make nodeLabelPlain optional
config: make nodeLabelImage optional
config: make imageFormat optional
config: make anonMode optional
config: make images still on by default, but optional
config: make layoutMaxSiblingDepth optional and give it a dynamic default
test: clean up comments from config files in testcases, except the screenshot one
config: make layoutMaxSiblingFamilyDepth optional