Added a few get methods for accessing private variables. Enables objects
to remove themselves and objects to access a couple map properties.
Created a new package for dialogs. Dialogs are modelled similarly to
discrete time Markov chains. DialogNode represents the structure of each
node and is in a finished state. DialogGraph contains methods for
loading graphs, saving graphs, starting graphs, creating graphs, and
editing graphs. Flow through dialogs is working except for strategy
selection. Other than that not much is completed. In the future there
will also be a graphical dialog maker tool.