Add start
Another step in the right direction
Register node and edge centrality tables
Handle database commits
Factor out node and edge centrality methods
Factor out create tables method
Extract analysis method
Make sure tables are registered correctly

It remains to check the results
Add unit test for unweighted case

Still need to check values
Check closeness in unit test
Check all closeness values
Check node betweenness (except for U)
Fix unit test for U

Important: See the proof of Theorem 6 in Brande's algorithm. He supposes
that on any shortest path from s to t containing v there is *exactly
one* edge {v,w} with v in P_s(w).

This is obviously false if there are multiple edges with the same
weight, as is the case in this example (U).

TODO? Adapt Brande's algorithm to this case.
Add DO paths in comment
Add WDO paths in comment
Add RO paths in comment
Add WRO paths in comment
Add U paths in comment
Add WU paths in comment
Add @author