Add simple nlogo file for benchmarking
WIP Get basic verification stuff working
Fix with-context implementation with new GraphContext implementation

Also fix edges implementation when given a turtle not in the context
Use monitoring for faster verification
Add single-source and single-dest tests to timeit
Add clique tests
Add graph path cache
Remove old distance class
Fix clique behavior on mixed directedness
Add failing mixed closeness centrality test
Add model for testing building and testing networks
Add some performance language tests
Improve Network Builder
Fix caching bfs path reconstruction and actually use it for primitives
Implement double caching stuff
Make cache selection a little smarter
Add benchmark models. Remove performance tests from language tests.
Put benchmarks in benchmarks folder so they can be run from nw's sbt
Remove mixed directedness tests. Added as issues #108 and #109.
Make resize-world test independent of NetLogo bug #563