Class added for making this multi-threaded
class added that extends the Jung graph class we use
exception class added for pubmed pagerank
class for setting up logging
lists files not to include in git
first version with multi-threading.  Normally jars would not be added, but it makes it easier for pulling down to run on another machine
added documentation
made this the worker class for multi-threading version
added constructor, reset method, and getmethod
removed hello world app in src
removed empty test for hello world app in src