Just some utilities and non-important additions

I added a Vector3i-class, which can nearly everything as the
Vector3f-class, but with Integers. This should be helpful when dealing
with MC-Coordinates.
I also added some utility to existing classes, mostly not really
important (like toString in RoutingEntry), but necessary for my next
commit to work.
Building the RoutingTable works

I successfully managed to build the routing table going from a
batterycharger to a wire in any distance (but still connected to a
network).
What does NOT work is the removing (NYI). This is what im working on
now.