Fixed backtracking in graph.shortest_path.
Added config.py to centralize configurations like project-root-directory and connections to the database.
Prune the dataset: 1. save a casting only if billing position > 0, 2. identify and remove movies that exhibit "dup castings", 3. filter by actors who starred in the top N billing positions in at least one movie (where N is parameterized).
Added test case for parsing IMDB data.
Lookup actor id by name.
Added a REST service to access the graph.
"graph" was renamed to "shortest_path".
Recommitting two .py files.  A git-move had went sour.
Added HTML server to display shortest paths between two actors.