gratr19 0.4.4.1

GRATR is a framework for graph data structures and algorithms. This library is a fork of RGL. This version utilizes Ruby blocks and duck typing to greatly simplfy the code. It also supports export to DOT format for display as graphics. GRATR currently contains a core set of algorithm patterns: * Breadth First Search * Depth First Search * A* Search * Floyd-Warshall * Best First Search * Djikstra's Algorithm * Lexicographic Search The algorithm patterns by themselves do not compute any meaningful quantities over graphs, they are merely building blocks for constructing graph algorithms. The graph algorithms in GRATR currently include: * Topological Sort * Strongly Connected Components * Transitive Closure * Rural Chinese Postman * Biconnected