add first set-context test
listen to agentset changes from GraphContext
remove some whitespace from README.md
remove ref to forked Jung in README.md
add set-context test for closeness centrality
remove some whitespace in tests.txt
don't cache Dijkstra objects for weighted graphs
add test for context after world resize
split Dijkstra between weighted/unweighted versions
add InvalidatableGraph trait
use InvalidatableGraph to reset context
add __show-context prim