Started work on global declaration importing. Restructured neo4j importer and reduced code duplication by defining an abstract base class for importers.
Leveraged Importer basis class to further reduce code duplication in neo4j importer and link declarations to the classes they appear in.
global declaration statement nodes are already in the database and we're now ready to add the actual declarations.
Global declaration import done. We will want to attach this to the corresponding AST at some point.