Moved WindowInformation to the general squall.orchestrate package, updating imports, as it is a very generic concept within squall.
Made the children, parents and childEdges of DGNode protected, in order to make them available to its descendants that may originate in sub packages of squall.orchestrate.
Added interfaces for the SteM data structure to the generic squall.orchestrate package, for future use when implementing eddies, or just migrating away from Jena at all.