Rework

[pranavtbhat]

Generalize the framework and bring it into a working condition.

• [x] Decide on a graph representation.
• [x] Decide on a auxiliary representation.
• [x] Create an independent message passing interface. (w/o global variables).
• [x] Find a solution to the local/global indexing.
• [x] Implement show methods for all user-defined data types.
• [x] Error handling to ensure safe movement of remote exceptions.
• [x] Work out BSP iterations (when to terminate and how to pass in data).
• [x] Demonstrate connected components using min vertex label propagation.
• [x] Demonstrate a working BFS implementation.