reformatted neo4j support source code; made neo4j support compliant with latest interfaces
reformatted source code; minor changes to support memgraph; eliminate a divide by zero crash of LoadCSV and LoadMetis against a fast implementation
added toString method to MemGraph vertex and edge classes so that the graph listings in Gremlin look nicer
bin/gremlin now creates neo4jstores and nativestore subdirectory; slight improvement to demo
switched demo to use PropelGraph