CHANGED: Graphs - Code cleanup.
ADDED: Graph - Unit tests.
CHANGED: Graph - Adding undirected edges no longer increased the edge count by two.
CHANGED: Graph - AdjacentVertices and IncidentEdges now return collections instead of enumerables.
ADDED: Graphs - Unit tests for multigraphs and loops.
CHANGED: 2D Packing - Code cleanup.
ADDED: Graphs - README file.