Consensus api

The api paradigm was switched up, and I moved over the consensus api calls. The one thing we haven't figured out is how to return an error string when the api call fails. I'm not sure what is idiomatic, but I would want to be as idiomatic and RESTful as possible.

I added a profiling package that should make profiling a lot easier. Siad, when passed a profiling flag, will make a log with basic profiling information.

There are additional calls that make it easy to start and stop memory and cpu profiling.

http/pprof is not used anywhere currently. Profiling is not done by default. The log sizes are pretty small even if you do turn on profiling.