Implemented first part of #17: A HierarchyModifier can now be specified instead of the eliminateHierarchy boolean flag. No new functionality is yet added.

fixed connectTo() so it now uses the dynamic/virtual model and thus obeys e.g. eliminated hierarchies etc.

introduced a ModuleGroup (grouping ApplicationModules and other ModuleGroups) and enforced a proper hierarchy of modules to exclude that an ApplicationModule can own (directly or indirectly) another ApplicationModule