Merge branch 'DefaultTopologyComponent-SisFix' into 'master'

Clone currentView -graph in DefaultTopologyComponent. getLocalView, so each requester receives a different object

Prevents several Requesters from receiving the very same Graph object.

When several instances request a `SiSTypes.NEIGHBORS_WIFI` object or otherwise access `DefautlTopologyComponent.getLocalView()` at the same time, i.e., before any changes to the underlay occur, they would receive the same snapshot object.

Changes to this object, like `getLocalView(nodeID, hopcount)`, `addElement` or `removeElement` would alter the graph at every receiver.

See merge request !1