added drag for cluster cube restrictor, when ctrl pressed drag changes size not position
shape and size of cluster now matches its restrictor - if it has one
changed default path for loading new graph
FIX - fixed clusers hanging in visualisation even after changing to different graph or clustering again; fixed seg fault when removing cluster restrictions
cluster cube restrictor and its nodes are now hidden - because the cluster visualizes restricting anyway
FIX - fixed some app crashes due to null pointer exceptions
added test if point is inside cube; fixed coordinates of new points inside cube restriction