Implemented zmqWorker and RequestHandler with a background threat updating the DB
Bugfix: updated DeleteEdgeTest to the new API ÃpassingVote to getCommonNodes
Moved LevelDbHandler into its own project: db-helper
Updated to muid 0.2.0
Merge branch 'feature/zmqWorker' into develop
Made updateAllNodes obsolete: while creating new edges not only all outgoind edges are updated but also all incoming ones. As this takes some time the server now runs write requests asynchroneously
Added updateAllNodes again as it could be usefull for large nodes