Debugged dynamic routing. It seems to be working.

After debugging my initial implementation of dynamic routing, the simulation
seems to work with FAST TCP. One notable change is that routers converge
based on a timeout rather than a given number of sequential nonupdates. I also
made a change in Network.simulate to begin the Bellman-Ford updates.
Merge branch 'dynamic_routing' of https://github.com/WalkerMills/network_simulator into dynamic_routing

Conflicts:
	process.py