[WIP] Validator Client: Validator's thinking for themselves.

[djrtwo]

Things:

• ValidatorClient is the software running the validator, making messages, etc. It inherits from Thread so it can be run in as a thread, executing it's run method, or it can just run as a regular object.
• Now two types of simulations: single-threaded and multi-threaded. Can be specified when running casper.py via --simulator
• Notes on multi-threaded args:
  • --rounds is the number of seconds to run
  • --report-interval is how often to graph frames in seconds
  • --rounds 60 --report-interval 1 will run a simulation of 60 seconds and create an output frame to the gif at every 1 second interval.
  • --hide-display is unnecessary. Does not hve the ability to do a tkinter display during running
  • --save True saves the gif
• Clock is a dumb interface to time for our objects. A clock relies on some external actor to update it's time. In the single-threaded simulation, the simulation-runner updates it explicitly, because the sim-runner is the central coordinator. In the multi-threaded simulation, the ValidatorClient thread updates its own clock each time it goes through its run loop.
• More thoughts on timing: Currently, ValidatorClient's update their Clock with process_time which makes these clocks not particularly interesting because all the threads share the same process_time. Need to look into alternative timing mechanisms. Threads are only somewhat interesting anyway. More exciting would be to have components in their own process...
• Message strategies are currently just monkey patched into ValidatorClients should_make_new_message method, but I'd like to move to specifying a more generic Strategy class that is passed to the ValidatorClient and encapsulates the logic of when to make a message

Threaded simulation sample run:

python casper.py rand --protocol blockchain --validators 5 --rounds 20 --report-interval 1 --hide-display --save True --network linear --simulator multi-threaded

TODO:

• Add a Module for handling more sophisticated message creation strategies.

[djrtwo]

@naterush See above notes about this PR.